Question
Train ‘A’ running with a speed of 54 km/hr. can
cross a standing goods train of 4 times its length in 20 seconds. Find the time taken by 240 meters long train ‘B’ which is coming from the opposite direction of train ‘A’, with a speed of 9 m/s, to cross-train ‘A’.Solution
Let the length of train ‘A’ be ‘x’ meters. Therefore, the length of the goods train = ‘4x’ meters Speed of train ‘A’ = 54 × (5/18) = 15 m/s According to the question, 4x + x = 15 × 20 => 5x = 300 => x = 60 Therefore, the time is taken by train ‘B’ to cross train ‘A’ = {(60 + 240)/ (15 + 9)}  = 300/24=50/4=12.5second
Find the missing number in the given number series.
2, 5, 11, 23, 47, ?120, 115, 120, 135, 160, ?
5, 6, 14, 45, ?, 925
? , 864, 432, 144, 36, 7.2
What will come in place of the question mark (?) in the following series?
92, 153, 220, ?, 364, 443
31, 60, 118, 234, 466, ?
166    156    136   ?     66    16
- What will come in place of the question mark (?) in the following series?
6, 6, 9, ?, 32, 56 7    8     ?     13     17     22    28
...- What will come in place of the question mark (?) in the following series?
6, 24, 60, ?, 210, 336
