Ques: A 600 meter long train crosses a signal post in 50 seconds. How long will it take to cross a 3 kilometer long bridge, at the same speed?
Options:
(A) 4 min
(B) 2 min
(C) 8 min
(D) 9 min
(E) 5 min
Ans: (E)
CoT: S = 600/50 = 12 mps
S = 3600/12 = 300 sec = 5 min

Ques: Find the number which when added to itself 13 times, gives 112.
Options:
(A) 7
(B) 8
(C) 9
(D) 10
(E) 11
Ans: (B)
CoT: Let the number be x. Then, x + 13x = 112 14x = 112 x = 8.

Ques: The average of first 10 odd numbers is?
Options:
(A) 44
(B) 10
(C) 99
(D) 77
(E) 62
Ans: (B)
CoT: Sum of 10 odd no. = 100
Average = 100/10 = 10

Ques: Two trains are moving at 50 kmph and 70 kmph in opposite directions. Their lengths are 150 m and 100 m respectively. The time they will take to pass each other completely is?
Options:
(A) 7 1/2 sec
(B) 2 sec
(C) 3 sec
(D) 5 sec
(E) 7 sec
Ans: (A)
CoT: 70 + 50 = 120 * 5/18 = 100/3 mps
D = 150 + 100 = 250 m
T = 250 * 3/100 = 15/2 = 7 sec