question: A can do a job in 12 days and B can do it in 20 days. A and B working together will finish twice the amount of work in days?
Options:
(A) 22 1/6
(B) 22 1/2
(C) 22 1/0
(D) 15
(E) 22 1/1
answer: Stream of consciousness: 1/12 + 1/20 = 8/60 = 2/15
15/2 = 15/2 *2 = 15 days The answer is (D).


q: A train 360 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
Options:
(A) 40 sec
(B) 32 sec
(C) 12 sec
(D) 85 sec
(E) 56 sec
a: Stream of consciousness: Answer: Option A
Speed = 45 * 5/18 = 25/2 m/sec
Total distance covered = 360 + 140 = 500 m
Required time = 500 * 2/25 = 40 sec The answer is (A).


question: What is the sum of all the composite numbers up to 20?
Options:
(A) 130
(B) 132
(C) 124
(D) 145
(E) 166
answer: Stream of consciousness: 4 + 6 + 8 + 9 + 10 + 12 + 14 + 15 + 16 + 18 = 132 The answer is (B).


q: Suppose you have three identical prisms with congruent equilateral triangles as the end-polygons. Suppose you attach them by the rectangular faces so they are perfectly aligned. There will be some large faces created by two or more co-planar faces of the individual prisms: count each such large face as one. Given that, how many faces does the resultant solid have
Options:
(A)  4
(B)  6
(C)  9
(D)  10
(E)  5
a: Stream of consciousness: To arrange them as described I did as follows on my scratch paper (see the file attached), where I counted 4 sides and bottom, hence 4+1 = 5. The answer is (E).


question: The radius of a cone is 4 m, height 5 m. Find the curved surface area?
Options:
(A) 1
(B) 3
(C) 5
(D) 7
(E) 9
answer: Stream of consciousness: Cone curved surface area = πrl = 22/7 × 4 × 5 = 440/7 = 62 6/7
Slant height (l) = √r(power2)+h(power2) = √16+9 = √25 = 5 The answer is (C).


question: Out of 7 consonants and 4 vowels, how many words of 3 consonants and 2 vowels can be formed?
Options:
(A) 25200
(B) 2543
(C) 2344
(D) 233445
(E) 52757
answer:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Stream of consciousness: Number of ways of selecting (3 consonants out of 7) and (2 vowels out of 4) = (7C3 x 4C2) = ( 7 x 6 x 5 x 4 x 3 ) 3 x 2 x 1 2 x 1 = 210. Number of groups, each having 3 consonants and 2 vowels = 210. Each group contains 5 letters. Number of ways of arranging 5 letters among themselves = 5! = 5 x 4 x 3 x 2 x 1 = 120. Required number of ways = (210 x 120) = 25200. The answer is (A).