Question

A can do a certain job in 12 days. B is 60% more efficient than A. To do the same job B alone would take?

• A. $$7\frac{1}{2}$ days$
• B. 8 days
• C. 10 days
• D. 7 days

Answer 1

Answer:

$$7\frac{1}{2}$ days$

Solution:

Given:

A can do a certain job in 12 days.

B is 60% more efficient than A.

Formula used:

work = efficiency × days

Calculation:

Let efficiency of A be 100.

The efficiency of B will be 160.

Ratio of efficiency A and B = 100 : 160 = 5 : 8

Total work = efficiency ratio of A × total days taken by A to finish work

⇒ 5 × 12 = 60 unit

Time taken by B to finish work = total work/efficiency ratio of B

$\frac{60}{8}=7\frac{1}{2}days$

B will finish the job in $7\frac{1}{2}days$