Question

Pintu takes 6 days more than those of Nishu to complete a certain work .If they work together they finish it in 4 days. How many days would it take to complete the work if they work alone.

Answer 1

Let Pintu take = x days

Nishu takes = (x - 6) days

In one day

Pintu does = 1/x

Nishu does = 1/(x - 6)

The two together do 1/x + 1(x - 6), and they take 4 days;

So

1/x + 1(x - 6) = 1/4

8x - 24 = x² - 6x

x² -14 + 24 = 0

x² - 2x - 12x + 24 = 0

x(x - 2) - 12(x - 2) = 0

(x - 12)(x - 2) = 0

Either

x - 12 = 0

x = 12

or

x - 2 = 0

x = 2

x can not be 2, so we take x = 12

Pintu alone takes = 12 days

Nishu alone takes = 12 - 6 = 6 days