Chain Rule - General Aptitude

Q1:

A man completes  of a job in 10 days. At this rate, how many more days will it takes him to finish the job?

A 5

B 6

C 7

D
7 1
2

ANS:B - 6

Work done = 5
8
Balance work = 1 - 5 = 3
8 8
Let the required number of days be x.
Then, 5 : 3 :: 10 : x      5 x = 3 x 10
8 8 8 8
 x = 3 x 10 x 8
8 5
 x = 6.