question:A can do a work in 9 days and B can do the same work in 18 days. If they work together, in how many days will they complete the work?
Options:
(A) 6 days
(B) 7 days
(C) 5 days
(D) 3 days
(E) 2 days
answer:(A)
Stream of consciousness:One day's work of A and B = 1/9 + 1/8 = (2+1)/18 = 1/6 So, the time taken to complete the work is 6 days.

question:Two persons A and B can complete a piece of work in 30 days and 45 days respectively. If they work together, what part of the work will be completed in 3 days?
Options:
(A) 1/5
(B) 1/1
(C) 1/6
(D) 1/3
(E) 1/7
answer:(C)
Stream of consciousness:A's one day's work = 1/30
B's one day's work = 1/45
(A + B)'s one day's work = 1/30 + 1/45 = 1/18
The part of the work completed in 3 days = 3 (1/18) = 1/6.

question:How many positive integers less than 60 have a reminder 01 when divided by 3?
Options:
(A) 13
(B) 14
(C) 15
(D) 16
(E) 20
answer:
(E)
Stream of consciousness:1 also gives the remainder of 1 when divided by 3. So, there are total of 20 numbers.