Question

1.Ram starts working on a job and works on it for 12 days and completes 40% of the work. To help him complete the work, he employs Ravi and together they work for another 12 days and the work gets completed. How much more efficient is Ram than Ravi?
A.50%
B.200%
C.125%
D.100%

Answer 1

D)100 % is the right answer
as 
time taken by ravi to compelete the work= (12/40)*100 =30 days
workin together they took = (12/60)*100 = 20 days
So let time taken by ravi to complete the entire work = x
so-
1/30+1/x = 1/20
then 1/x = 1/20-1/30=1/60
therefore,x=60
hence ram hase 100 % more efficiency 

Answer 2

D)100 % is the right answer
as 
time taken by ravi to compelete the work= (12/40)*100 =30 days
workin together they took = (12/60)*100 = 20 days
So let time taken by ravi to complete the entire work = x
so-
1/30+1/x = 1/20
then 1/x = 1/20-1/30=1/60
therefore,x=60
hence ram hase 100 % more efficiency