Question : A and B can do a piece of work in 25 days. B alone can do
Option 1: 18
Option 2: 15
Option 3: 12
Option 4: 20
Correct Answer: 15
Solution :
Days taken by A and B together to do total work = 25 days
Days taken by B to do =
We know,
Number of days taken =
Days taken by B to do
⇒ Days taken by B to do total work =
Let the total work be LCM of 25 and 45 = 225 units
The efficiency of A and B together =
The efficiency of B =
The efficiency of A = 9 – 5 = 4
Days taken by A to do
Hence, the correct answer is 15 days.
