Four persons work independently of each other on a task. If the probabilities that they will complete the task are : (1)/(2),(1)/(3),(1)/(4) and (1)/(5) , then the probability, that at least one of them will complete it, is

Probability: Four persons work independently of each other on a task. If the… | JEE Main 2021

JEE Main 2021 (Online) 4th August Morning ShiftQuestion 1

Four persons work independently of each other on a task. If the probabilities that they will complete the task are : $\frac{1}{2},\frac{1}{3},\frac{1}{4}$ and $\frac{1}{5}$, then the probability, that at least one of them will complete it, is

Probability

$0.2$$0.8$✓ Correct answer$0.4$$0.6$

Solution

$P(\text{none})=\frac12\cdot\frac23\cdot\frac34\cdot\frac45=\frac15$. $P(\text{at least one})=1-\frac15=0.8$. Option B.

Probability - JEE Mathematics question (JEE Main 2021 (Online) 4th August Morning Shift)

More from Probability