q: Efrida and Frazer who live 15 miles apart, meet at a restaurant that is directly north of Efrida's home and directly east of Frazer's home. If the restaurant is two miles closer to Efrida's home, than to Frazer's home, how many miles is the restaurant from Frazer's home?
Options:
(A) 6
(B) 7
(C) 8
(D) 10
(E) 13
a: It's a simple geometry problem. Look at the diagram below: The answer is (E).
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q: A train running at the speed of 60 km/hr crosses a pole in 9 sec. What is the length of the train?
Options:
(A) 120 m
(B) 190 m
(C) 115 m
(D) 110 m
(E) 150 m
a: Speed = 60 * 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 9 = 150 m The answer is (E).
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q: The average of 21 numbers is 25. The average of first ten numbers is 18 and the average of last ten numbers is 32. What is the middle number?
Options:
(A) 195
(B) 175
(C) 184
(D) 201
(E) 188
a: The total of 21 numbers = 21X25 = 525
The total of first 10 and last 10 numbers is = 10 X 14+10 X 19 = 330
So, the middle number is (525 - 330 ) = 195 The answer is (A).
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q: A box contains nine bulbs out of which 4 are defective. If four bulbs are chosen at random, find the probability that atleast one bulb is good.
Options:
(A) 125/127
(B) 127/125
(C) 125/126
(D) 126/125
(E) 126/127
a:
Required probability = 1 - 1/126 = 125/126 The answer is (C).
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