Question

Pooja and Ritu can do a piece of work in 20/7 days . If one day work of Pooja be three fourth of one day work of Ritu. Find in how many days each will take to do the work alone.

Answer 1

Let the total work be w

let the work done by pooja in a day be w / a

let the work done by Ritu in a day be w / b

given they complete the work in 20 / 7 days

=> (w / a + w / b ) * 20 / 7 = w

=> 1 / a + 1/ b = 7/20

given one day work of pooja be three fourth of one day work of Ritu

=> w / a = 3 w / 4b

=> 1 / a =  3 / 4b 

now substituting it

=> 3 / 4b + 1/b = 7 / 20
=> 7 / 4b = 7 / 20
=> 4b = 20
=> b = 5
so a will be 20 / 3

 => pooja need 20/3 days and ritu need 5 days each to complete the work