[Ans] (D)
[Question] If L is the least positive integer that is divisible by every integer from 1 to 9 inclusive, then L/2 is =
Options:
(A) 5040
(B) 2520
(C) 1890
(D) 1260
(E) 630
[CoT] The integer should be divisible by: 2, 3, 4, 5, 6, 7, 8 and 9, that is 2, 3, 2^2, 5, 2*3, 7, 2^3 and 3^2. The least common multiple of these integers is the product of 7, 5, 3^2 and 2^3. Then, L/2 is (7 * 5 * 3^2 * 2^3)/2 = 7*5*9*4 = 1260.

[Ans] (E)
[Question] A train is running at a speed of 40 km/hr and it crosses a post in 18 seconds. What is the length of the train?
Options:
(A) 190 metres
(B) 160 metres
(C) 180 metres
(D) 120 metres
(E) 200 metres
[CoT] Speed of the train, v = 40 km/hr = 40000/3600 m/s = 400/36 m/s
Time taken to cross, t = 18 s
Distance Covered, d = vt = (400/36) 18 = 200 m
Distance covered is equal to the length of the train = 200 m

[Ans] (E)
[Question]
If a man can cover 16 metres in one second, how many kilometres can he cover in 3 hours 45 minutes?
Options:
(A) 180km
(B) 190km
(C) 200km
(D) 210km
(E) 216km
[CoT] 16 m/s = 16 * 18/5 kmph
3 hours 45 minutes = 3 3/4 hours = 15/4 hours
Distance = speed * time = 16 * 18/5 * 15/4 km = 216 km.