question: The edge of a cube is 6a cm. Find its surface?
Options:
(A) 216a2
(B) 24a4
(C) 24a1
(D) 24a2
(E) 24a7
answer: Stream of consciousness: 6a2 = 6 * 6a * 6a = 216a2 The answer is (A).

q: The average of 9 observations was 9, that of the 1st of 5 being 10 and that of the last 5 being 8. What was the 5th observation?
Options:
(A) 9
(B) 8
(C) 7
(D) 6
(E) 4
a: Stream of consciousness: 1 to 9 = 9 * 9 = 81
1 to 5 = 5 * 10 = 50
5 to 9 = 5 * 8 = 40
5th = 50 + 40 = 90 81 = 9 The answer is (A).

question: A number lock on a suitcase has 3 wheels each labelled with 10 digits from 0 to 9. If opening of the lock is a particular sequence of three digits with no repeats, how many such sequences will be possible?
Options:
(A) 720
(B) 760
(C) 680
(D) 780
(E) 880
answer: Stream of consciousness: On first wheel there can be 10 digits. On the second wheel there will be one of the 9 digits and on the third wheel there will be 8 digits. Therefore, the number of numbers is
10 x 9 x 8 = 720 The answer is (A).

q: a piece of ribbon 4 yard long is used to make bows requiring 15 inches of ribbon for each.What is the maximum number of bows that can be made.
Options:
(A) 9
(B) 8
(C) 7
(D) 6
(E) 5
a: Stream of consciousness: 1 yard = 36 Inch
4 yard = 36*4 = 144 inch
15 inch req. for 1 bow
Max. no. of bows possible = 144/15 = 9 bows and 9 inch ribbon left. The answer is (A).

question: The speed of a boat in still water is 90kmph and the speed of the current is 20kmph. Find the speed downstream and upstream?
Options:
(A) 40, 68 kmph
(B) 110, 70 kmph
(C) 90, 60 kmph
(D) 40, 60 kmph
(E) 20, 60 kmph
answer: Stream of consciousness: Speed downstream = 90 + 20 = 110 kmph
Speed upstream = 90 - 20 = 70 kmph The answer is (B).

question: Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?
Options:
(A) 299
(B) 2767
(C) 120
(D) 287
(E) 261
answer:
Stream of consciousness: Work done by the waste pipe in 1 minute = 1/15 - (1/20 + 1/24) = - 1/40
Volume of 1/40 part = 3 gallonsVolume of whole = 3 * 40 = 120 gallons. The answer is (C).