question: Three 6 faced dice are thrown together. The probability that exactly two dice show the same number on them is ?
Options:
(A) 5/16
(B) 5/12
(C) 5/87
(D) 5/56
(E) 5/38
answer: Stream of consciousness: Using question number 11 and 12, we get the probability as
1 - (1/36 + 5/9) = 5/12 The answer is (B).

q: Eddy and Freddy start simultaneously from city A and they travel to City B and City C respectively. Eddy takes 3 hours and Freddy takes 4 hours to complete the journey. If the distance between City A and City B is 480 kms and City A and City C is 300 kms. What is the ratio of their average speed of travel? (Eddy: Freddy)
Options:
(A) 32/15
(B) 3/8
(C) 8/5
(D) 5/8
(E) 5/3
a: Stream of consciousness: Distance traveled by Eddy = 480 km
Time taken by Eddy = 3 hours
Average speed of Eddy = 480/3 = 160 km/hour
Distance traveled by Freddy = 300 km
Time taken by Freddy = 4 hours
Average speed of Freddy = 300/4 = 75 km/hour
Ratio of average speed of Eddy to Freddy = 160/75 = 32/15 The answer is (A).

question: Five coins are tossed simultaneously. In how many of the outcomes will the third coin turn up a head?
Options:
(A) 2^4
(B) 2^10
(C) 3 * 2^8
(D) 3 * 2^9
(E) 3 * 2^10
answer: Stream of consciousness: Fix the third coin as H. The remaining 4 coins have 2^4 outcomes. The answer is (A).

q: Find the invalid no.from the following series 13, 18, 25, 30, 37, 40
Options:
(A) 21
(B) 25
(C) 40
(D) 47
(E) 58
a: Stream of consciousness: The differences between two successive terms from the beginning are 7, 5, 7, 5, 7, 5. So, 40 is wrong. The answer is (C).

question: If six persons sit in a row, then the probability that three particular persons are always together is
Options:
(A) 1/20
(B) 3/10
(C) 1/5
(D) 4/5
(E) 2/5
answer: Stream of consciousness: Six persons can be arranged in a row in 6! ways. Treat the three persons to sit together as one unit then there four persons and they can be arranged in 4! ways. Again three persons can be arranged among them selves in 3! ways. Favourable outcomes = 3!4! Required probability = 3!4!/6! = 1/5 The answer is (C).

question: A certain car uses 12 gallons of gasoline in traveling 120 miles. In order for the car to travel the same distance using 10 gallons of gasoline, by how many miles per gallon must the car's gas mileage be increased?
Options:
(A) 2
(B) 4
(C) 6
(D) 8
(E) 10
answer:
Stream of consciousness: 120/10 = 12. The difference is 12- 10 = 2. The answer is (A).