Question

Puja is 30% less efficient than Poonam. If Poonam takes 20 days to do a job, how many days would Puja take to do the work.

विकल्प

• 26 days

• `28 4/7` days

• `22  1/3` days

• Cannot be determined

Answer 1

`28 4/7` days

Explanation:

Ratio of efficiency of Puja : Poonam

= 0.7 : 1 or 7 : 10

Ratio of time of Puja : Poonam = 10 : 7

When poonam takes 20 days, hence 7x

= 20, x = `20/7` and no. of days taken by puja = `(10 * 20)/7`

`= 200/7 = 28  4/7` days