John makes $50 a week from his job. He earns a raise and now makes $70 a week. What is the % increase?
Options:
(A) 16%
(B) 16.66%
(C) 18%
(D) 21%
(E) 40%
Answer and stream of consciousness: (E)
Stream of consciousness: Increase = (20/50)*100 = 40%.

X can finish a work in 18 days. Y can finish the same work in 15 days. Yworked for 10 days and left the job. how many days does X alone need to finish the remaining work?
Options:
(A) 1
(B) 3
(C) 6
(D) 8
(E) 9
Answer and stream of consciousness: (C)
Stream of consciousness: Work done by X in 1 day = 1/18
Work done by Y in 1 day = 1/15
Work done by Y in 10 days = 10/15 = 2/3
Remaining work = 1 2/3 = 1/3
Number of days in which X can finish the remaining work = (1/3) / (1/18) = 6

Dacid obtained 76, 65, 82, 67 and 85 marks (out of 100) in English, Mathematics, Physics, Chemistry and Biology. What are his average marks?
Options:
(A) 75
(B) 45
(C) 23
(D) 28
(E) 96
Answer and stream of consciousness: (A)
Stream of consciousness: Average = (76 + 65 + 82 + 67 + 85)/5 = 375/5 = 75.

There are 15 balls in a jar. You take out 3 blue balls without putting them back inside, and now the probability of pulling out a blue ball is 1/3. How many blue balls were there in the beginning?
Options:
(A) 12.
(B) 9.
(C) 8.
(D) 7.
(E) 6.
Answer and stream of consciousness:
(D)
Stream of consciousness: 7 = 3 blue balls + 12 / 3