Read the text carefully and answer the questions :
Three persons A, B and C were given a task, whose probabilities of completion their task on time are $\frac{1}{3}, \frac{1}{4}$ and $\frac{1}{5}$ respectively. They were asked to complete the task on time independently.
The probability that task is completed on time by at least one of them is:
Answer & explanation
Correct answer: option 3
P(task is completed atleast once) = 1 - P(no one completes the task)
$=1-\frac{2}{5}=\frac{3}{5}$
Option: 3