Question

Q.17 Amit is twice efficient as Ravi and together they do the same
work in as much time as Chitra and Dravid together. If Chitra and
Dravid can complete the work in 20 and 30 days respectively, working
alone, then in how many days Amit can complete the work alone?
(a) 22 days (b) 18 days (c) 20 days (d) 10 days (e)None of these​

Answer 1

Answer:

b. 18 days

Step-by-step explanation:

1/x+1/(2x) = 1/20+1/30

Multiply all terms by x and cancel

1+1/2=1x/20+1x/30

3/2=(1/12)x

x=12*(3/2)

x=18

All the best!