Mathematics · Probability

At Least One Event from Failure Probabilities failure probability for second independent event Solver

Rearrange the at least one event from failure probabilities relationship and solve for failure probability for second independent event.

Runs locally
Your numbers

Inputs and results stay in this browser. Change one value at a time to explore the relationship.

Your inputCalculatedPassed forward in chains
failure probability for second independent event0.8
Reconstructed probability of at least one success0.44

Calculation steps

  1. Use b=(1−c)/a with probability of at least one success=0.44000000000000006 and failure probability for first independent event=0.7.
  2. failure probability for second independent event=0.7999999999999999.
  3. Substitution into c=1−ab reconstructs 0.44000000000000006.

Understand At Least One Event from Failure Probabilities: solve failure probability for second independent event

One idea, three depths

Choose how deeply to explain At Least One Event from Failure Probabilities: solve failure probability for second independent event

At Least One Event from Failure Probabilities: solve failure probability for second independent event: Rearrange the at least one event from failure probabilities relationship and solve for failure probability for second independent event.

Age 5Explain it to a 5-year-oldStart with a picture

Imagine using At Least One Event from Failure Probabilities: solve failure probability for second independent event to answer this question: rearrange the at least one event from failure probabilities relationship and solve for failure probability for second independent event? Enter probability of at least one success and failure probability for first independent event; the calculator shows failure probability for second independent event. For example: failure probability for first independent event=0.7 and failure probability for second independent event=0.8 produce probability of at least one success=0.44000000000000006. The answer tells you failure probability for second independent event.

Age 15Explain it to a 15-year-oldConnect it to the formula

For two independent trials, one minus the probability that both fail gives the probability of at least one success. This page isolates failure probability for second independent event and verifies it in the original relationship. The rule is b=(1−c)/a. Its input values are probability of at least one success, failure probability for first independent event, and the main result is failure probability for second independent event. For example: failure probability for first independent event=0.7 and failure probability for second independent event=0.8 produce probability of at least one success=0.44000000000000006.

CollegeExplain it at college levelState the model precisely

This calculator evaluates the stated at least one event from failure probabilities: solve failure probability for second independent event relation over the valid real-number domain stated below. The implemented relation is b=(1−c)/a, evaluated from probability of at least one success, failure probability for first independent event to produce failure probability for second independent event. For two independent trials, one minus the probability that both fail gives the probability of at least one success. This page isolates failure probability for second independent event and verifies it in the original relationship. The inputs are failure probabilities and independence must be justified.

Inputs and valid domain

  • probability of at least one success must be a finite real number.
  • failure probability for first independent event must be a finite real number.

Important boundary: The inputs are failure probabilities and independence must be justified.

The formula

b=(1−c)/a

How the calculator works through it

It substitutes probability of at least one success, failure probability for first independent event into the formula and exposes every numerical step above. The main output is failure probability for second independent event, accompanied by Reconstructed probability of at least one success.

Read the result correctly

The failure probability for second independent event is the direct answer to “rearrange the at least one event from failure probabilities relationship and solve for failure probability for second independent event.” Read it with the units shown beside the inputs; a sign, angle, percentage or rate changes what the number means.

A worked check

failure probability for first independent event=0.7 and failure probability for second independent event=0.8 produce probability of at least one success=0.44000000000000006.

Where this model stops being reliable

The inputs are failure probabilities and independence must be justified.

Learn it by changing one value

Begin with the worked example, then change one value while keeping the others fixed. Compare the new result and calculation steps to identify which part of the formula changed.

Dictionary terms behind this calculator

Before studying the codeWhat you should know firstUse the calculator immediately, or check the foundations before reading the implementation.

These foundations help you understand why At Least One Event from Failure Probabilities: solve failure probability for second independent event works. They never block the calculator, and “optional” means useful context rather than a hidden requirement.

Hard requirements

  • Reading formulas and substituting values

    At Least One Event from Failure Probabilities: solve failure probability for second independent event uses b=(1−c)/a. You need to recognise what each side represents before substituting the stated inputs or rearranging the relationship.

    Review this foundation about 4 min

Strong support

  • Probability as a modelled proportion

    Probability rules are needed to interpret what the At Least One Event from Failure Probabilities: solve failure probability for second independent event result says about possible outcomes.

    Review this foundation about 5 min

Optional enrichment

  • Ordered arrangements

    Counting ordered arrangements can extend At Least One Event from Failure Probabilities: solve failure probability for second independent event to more detailed sample spaces and event models.

    Review this foundation about 5 min
Learn the missing foundationsI already know these — show the code

Mathematics → algorithm → program

Implement this calculation in code

These are direct reference implementations of the calculator's principal relationship and first output. They run locally and include a small known-answer check where the language supports it.

Algorithm

  1. Read probability of at least one success, failure probability for first independent event.
  2. Evaluate the principal relationship: b=(1−c)/a.
  3. Return failure probability for second independent event and check the domain conditions described above.
Python
            from math import *

def at_least_one_from_failure_probabilities_solve_b(c, a) -> float:
    return ((1.0 - c) / a)

assert abs(at_least_one_from_failure_probabilities_solve_b(0.44000000000000006, 0.7) - 0.7999999999999999) < 1e-6 * max(1.0, abs(0.7999999999999999))
          
Current calculator valuesUpdates when you change an input above.
              
            
C
            #include <assert.h>
#include <math.h>

double at_least_one_from_failure_probabilities_solve_b(double c, double a) {
    return ((1.0 - c) / a);
}

int main(void) {
    const double expected = 0.7999999999999999;
    const double actual = at_least_one_from_failure_probabilities_solve_b(0.44000000000000006, 0.7);
    assert(fabs(actual - expected) < 1e-6 * fmax(1.0, fabs(expected)));
}
          
Current calculator valuesUpdates when you change an input above.
              
            
C++
            #include <cassert>
#include <cmath>
#include <numbers>

double at_least_one_from_failure_probabilities_solve_b(double c, double a) {
    return ((1.0 - c) / a);
}

int main() {
    constexpr double expected = 0.7999999999999999;
    const double actual = at_least_one_from_failure_probabilities_solve_b(0.44000000000000006, 0.7);
    assert(std::fabs(actual - expected) < 1e-6 * std::fmax(1.0, std::fabs(expected)));
}
          
Current calculator valuesUpdates when you change an input above.
              
            
Linux x86-64 assembly

x86-64 NASM · System V ABI · Linux · SSE2 with libm where required

            ; double at_least_one_from_failure_probabilities_solve_b(double c, double a)
; Linux x86-64 NASM · System V ABI · first eight doubles in xmm0–xmm7
global at_least_one_from_failure_probabilities_solve_b
section .text

at_least_one_from_failure_probabilities_solve_b:
    push rbp
    mov rbp, rsp
    sub rsp, 48
    movsd [rbp-8], xmm0
    movsd [rbp-16], xmm1
    mov rax, 0x3ff0000000000000
    movq xmm0, rax
    movsd [rbp-40], xmm0
    movsd xmm0, [rbp-40]
    subsd xmm0, [rbp-8]
    movsd [rbp-32], xmm0
    movsd xmm0, [rbp-32]
    divsd xmm0, [rbp-16]
    movsd [rbp-24], xmm0
    movsd xmm0, [rbp-24]
    leave
    ret
          
Current calculator valuesUpdates when you change an input above.
              
            
MATLAB
            function result = at_least_one_from_failure_probabilities_solve_b(c, a)
    result = ((1.0 - c) / a);
end
          
Current calculator valuesUpdates when you change an input above.
              
            
Wolfram Language
            ClearAll[mwCalculate];
mwCalculate[c_, a_] := ((1.0 - c) / a);
          
Current calculator valuesUpdates when you change an input above.
              
            

Continue in mathematical software

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Supporting sourcesAcademic referencesPrimary standards, textbooks and complete citations

Standards, reading and academic references

Use the calculator as the worked interaction, then consult the primary standards and academic textbooks listed below. MW SysArc links to the original sources; the explanation on this page is original and does not reproduce them.

Introductory Statistics 2e

Read the free OpenStax statistics textbook
Cite this book
APA 7
Illowsky, B., & Dean, S. (2023). Introductory statistics 2e. OpenStax. https://openstax.org/books/introductory-statistics-2e/pages/1-introduction
MLA 9
Illowsky, Barbara, and Susan Dean. Introductory Statistics 2e. OpenStax, 2023, https://openstax.org/books/introductory-statistics-2e/pages/1-introduction.
Chicago author-date
Illowsky, Barbara, and Susan Dean. 2023. Introductory Statistics 2e. Houston, TX: OpenStax. https://openstax.org/books/introductory-statistics-2e/pages/1-introduction.

OpenStax entries are free to read online. Follow the licence shown on each linked source before redistributing or adapting its content.

Reuse the page responsiblyCite this pageAPA, MLA, Chicago, Harvard, BibTeX and RIS

These formats cite this calculator page itself. They are separate from the academic references above, which support the mathematical method and terminology.

APA 7

MW SysArc. (2026, July 21). At Least One Event from Failure Probabilities failure probability for second independent event Solver. MW SysArc Tools. https://math.mwsysarc.com/probability/at-least-one-from-failure-probabilities-failure-probability-for-second-independent-event-solver

MLA 9

MW SysArc. “At Least One Event from Failure Probabilities failure probability for second independent event Solver.” MW SysArc Tools, 21 July 2026, https://math.mwsysarc.com/probability/at-least-one-from-failure-probabilities-failure-probability-for-second-independent-event-solver. Accessed 31 Aug. 2026.

Chicago 17

MW SysArc. “At Least One Event from Failure Probabilities failure probability for second independent event Solver.” MW SysArc Tools. Published July 21, 2026. Accessed August 31, 2026. https://math.mwsysarc.com/probability/at-least-one-from-failure-probabilities-failure-probability-for-second-independent-event-solver.

Harvard

MW SysArc (2026) ‘At Least One Event from Failure Probabilities failure probability for second independent event Solver’, MW SysArc Tools. Published 21 July 2026. Available at: https://math.mwsysarc.com/probability/at-least-one-from-failure-probabilities-failure-probability-for-second-independent-event-solver (Accessed: 31 August 2026).

BibTeX and RIS records

BibTeX

@misc{mwsysarc_at_least_one_from_failure_probabilities_solve_b_2026,
  author = {{MW SysArc}},
  title = {At Least One Event from Failure Probabilities failure probability for second independent event Solver},
  howpublished = {MW SysArc Tools},
  year = {2026},
  url = {https://math.mwsysarc.com/probability/at-least-one-from-failure-probabilities-failure-probability-for-second-independent-event-solver},
  note = {Published July 21, 2026; accessed August 31, 2026}
}

RIS

TY  - ELEC
AU  - MW SysArc
TI  - At Least One Event from Failure Probabilities failure probability for second independent event Solver
T2  - MW SysArc Tools
PY  - 2026
DA  - 2026-07-21
Y2  - 2026-08-31
UR  - https://math.mwsysarc.com/probability/at-least-one-from-failure-probabilities-failure-probability-for-second-independent-event-solver
N1  - Published July 21, 2026
ER  -

Clear answers

Frequently asked questions

What does the At Least One Event from Failure Probabilities: solve failure probability for second independent event do?

Rearrange the at least one event from failure probabilities relationship and solve for failure probability for second independent event.

How does the At Least One Event from Failure Probabilities: solve failure probability for second independent event work?

The calculator applies b=(1−c)/a. For two independent trials, one minus the probability that both fail gives the probability of at least one success. This page isolates failure probability for second independent event and verifies it in the original relationship.

What can I learn from the At Least One Event from Failure Probabilities: solve failure probability for second independent event?

It connects the mathematical rule to your chosen numbers and shows each calculation step. Change one input at a time to see how the result responds.

Does MW SysArc receive or store what I enter?

No. The calculation runs locally in your browser. MW SysArc does not receive or store your calculation inputs.

How should I use the result?

Use the steps to understand the method, then verify important school or professional work using the notation and rounding rules required in your setting.

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