Question

Alex can solve a problem in 4 minutes. Brian can solve the same problem in ${\frac{1}{5}}^{th}$ of the time taken by Alex. How long does it take Brian to solve the problem?

• A. 27 sec
• B. 65 sec
• C. 48 sec
• D. 60 sec

Answer 1

The correct option is C 48 sec

Given that, the time taken by Alex to solve a problem is $4\times 60=240sec$

And Brian takes one-fifth of the time taken by Alex to solve this problem.
So, Time taken by Brian
$=\frac{1}{5}\times 240=\frac{240}{5}=48sec$

Hence, Brian takes 48 seconds to solve the problem.