Question

A and B working together can complete a job in 3 hours if a alone can do the job in seven half hours in how much time can be alone finish the job

Answer 1

5 h will be the answer

Answer 2

B alone can complete the work in "5 hours".

Step-by-step explanation:

We have,

(A + B)'s 1 hour's work = $\dfrac{1}{3}$ and

A's 1 hour's work $= \dfrac{2}{15}$

To find, the number of days B alone can complete the work = ?

∴ B's 1 hour's work =` (A + B)'s 1 hour's work - A's 1 hour's work

$= \dfrac{1}{3}-\dfrac{2}{15}$

$=\dfrac{5-2}{15} =\dfrac{3}{15}$

$=\dfrac{1}{5}$

Thus, B alone can complete the work in 5 hours.