Question

A and B can do a job together in 7 days. A is $1\frac{3}{4}$ times as efficient as B. The same job can be done by A alone in how many days?

• A. days
• B. 11 days
• C. days
• D. days
• E. 7 days

Answer 1

The correct option is B

11 days

(A’s 1 day’s work): (B’s 1 day’s work) be 7x and 4x respectively.

Let A’s and B’s 1 day’s work be 7x and 4x respectively.

Then,

$7x+4x=\frac{1}{7}\Rightarrow 11x=\frac{1}{7}\Rightarrow x=\frac{1}{77}$

∴ A’s 1 day’s work =

$(\frac{1}{77}\times 7)=\frac{1}{11}$

So, A will complete the work in 11 days.