A problem is given to three students whose chances of solving it are 1/2, 1/3 and 1/4 respectively. What is the probability that the problem will be solved?
Correct Answer: Option C
Let A, B, C be the respective events of solving the problem and
\(\overline{A\;},\;\overline B,\;\overline C\) be the respective events of not solving the problem. Then A, B, C are independent event
\(\overline{A\;},\;\overline B,\;\overline C\) are independent events
Now, P(A) = 1/2 , P(B) = 1/3 and P(C)=1/4
\(P\left(\overline A\right)=\frac12,\;P\left(\overline B\right)=\frac23,\;P\left(\overline C\right)=\;\frac34\)
P( none solves the problem) = P(not A) and (not B) and (not C)
= \(P\left(\overline A\cap\overline B\cap\overline C\right)\)
= \(P\left(\overline A\right)P\left(\overline B\right)P\left(\overline C\right)\)
\(\left[\because\;\overline A,\;\overline B,\;\overline C\;are\;Independent\right]\)
= \(\frac12\times\frac23\times\frac34\)
= \(\frac14\)
Hence, P(the problem will be solved) = 1 - P(none solves the problem)
= \(1-\frac14\) = = 3/4
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