q: How many seconds will a train 100 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph?
Options:
(A) 22
(B) 28
(C) 25
(D) 77
(E) 88
a: OK... D = 100 + 150 = 250
S = 36 * 5/18 = 10 mps
T = 250/10 = 25 se
The answer is (C).

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) 287
(B) 699
(C) 677
(D) 168
(E) 150
a: OK... Speed = 60 * 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 9 = 150 m
The answer is (E).

q: For every order, a certain mail-order company charges a shipping fee of $3 plus an additional $2 if the value of the order is over $50 but not over $100 or an additional $3 if the value of the order is over $100. How much greater are the total shipping fees for 2 orders of $75 each than the total shipping fee for 3 order of $150 ?
Options:
(A) $1
(B) $2
(C) $3
(D) $4
(E) $8
a:
OK... Total cost involved for each 75 $ shipment: 3+2 = 5 $. Thus, for two such orders = 10$
Total cost involved for a 150$ shipment: 3+3 = 6$. Thus, for two such orders = 18$
The difference = 8$.
The answer is (E).