question: There are 5 fictions and 6 non-fictions. How many cases are there such that 2 fictions and 2 non-fictions are selected from them?
Options:
(A) 90
(B) 120
(C) 150
(D) 180
(E) 200
answer: Stream of consciousness: Number of ways of selecting 2 fiction books = 5C2
Number of ways of selecting 2 non fiction books = 6C2
5C2 * 6C2 = 10 * 15 = 150 The answer is (C).

q: There are 5 sweets - Jammun, kaju, Peda, Ladu, Jilebi which can be consumed in 5 consecutive days. Monday to Friday. A person eats one sweet a day, based on the following constraints.
(i) Ladu not eaten on monday
(ii) If Jamun is eaten on Monday, Ladu should be eaten on friday.
(iii) Peda is eaten the day following the day of eating Jilebi
(iv) If Ladu eaten on tuesday, kaju should be eaten on monday
based on above, peda can be eaten on any day except
Options:
(A) monday
(B) tuesday
(C) tuWesday
(D) wednesday
(E) friday
a: Stream of consciousness: From the (iii) clue, peda must be eaten after jilebi. so Peda should not be eaten on monday. The answer is (A).

question: How much more would Rs.30000 fetch, after two years, if it is put at 20% p.a. compound interest payable half yearly than if is put at 20% p.a. compound interest payable yearly?
Options:
(A) 482
(B) 725
(C) 992
(D) 837
(E) 723
answer: Stream of consciousness: 30000(11/10)4 - 30000(6/5)2 = 723 The answer is (E).

q: The average height in a group of 4 people is 175 cm. If the average height increased when 2 more people were added to the group, which of the following cannot be the heights of the two new people?
Options:
(A) 179 cm and 172 cm
(B) 181 cm and 169 cm
(C) 173 cm and 178 cm
(D) 176 cm and 176 cm
(E) 174 cm and 177 cm
a: Stream of consciousness: Denote X as the sum of the heights of the two new people. From the stem it follows that (700+X)6>175. This reduces to X>350. Only the heights from B add up to 350 cm. All other pairs add up to more than 350 cm. The answer is (B).

question: The average of 13 result is 20. Average of the first 8 of them is 20 and that of the last 8 is 40. Find the 8th result?
Options:
(A) 35
(B) 37
(C) 46
(D) 90
(E) 100
answer: Stream of consciousness: Sum of all the 13 results = 13 * 20 = 260
Sum of the first 7 of them = 8 * 20 = 160
Sum of the last 7 of them = 8 * 40 = 320
So, the 8th number = 260 + 160 - 320 = 100. The answer is (E).

question: In what time will a railway train 50 m long moving at the rate of 36 kmph pass a telegraph post on its way?
Options:
(A) 5 sec
(B) 4 sec
(C) 3 sec
(D) 6 sec
(E) 1 sec
answer:
Stream of consciousness: T = 50/36 * 18/5 = 5 sec The answer is (A).