question:In each series, look for the degree and direction of change between the numbers. In other words, do the numbers increase or decrease, and by how much? Look at this series: 120, 30, 240, 25, ___, 20, 480, 15... Which number is missing?
Options:
(A) 120
(B) 360
(C) 340
(D) 960
(E) 280
answer:(B)
Stream of consciousness:B 360
This is an alternating addition and subtraction series. In the first pattern, 120 is added to each number to arrive at the next. In the second, 5 is subtracted from each number to arrive at the next.

question:How many seconds will a train 200 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph?
Options:
(A) 22 sec
(B) 35 sec
(C) 25 sec
(D) 18 sec
(E) 17 sec
answer:(B)
Stream of consciousness:D = 200 + 150 = 350
S = 36 * 5/18 = 10 mps
T = 350/10 = 35 sec

question:How many seconds will a train 120 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph?
Options:
(A) 27 sec
(B) 23 sec
(C) 24 sec
(D) 25 sec
(E) 26 sec
answer:
(A)
Stream of consciousness:D = 120 + 150 = 270
S = 36 * 5/18 = 10 mps
T = 270/10 = 27 sec