q: In what time will a cart 50 m long cross, if its speed be 36 km/hr?
Options:
(A) 25
(B) 5
(C) 15
(D) 20
(E) 30
a: OK... Speed = 36 * 5/18 = 10 m/sec
Time taken = 50/10 = 5 sec.
The answer is (B).

q: 5,9,17,29,49,__
Options:
(A) 79
(B) 80
(C) 81
(D) 82
(E) 83
a: OK... (9+5) +3 = 17
(16+9) +4 = 29
(28+16)+5 = 49
(48+28)+6 = 82
The answer is (D).

q: The simple interest on a sum of money is 4/9 of the principal and the number of years is equal to the rate percent. Find the rate and the time?
Options:
(A) 6 2/3%
(B) 6 2/8%
(C) 6 9/3%
(D) 6 2/3%
(E) 6 2/1%
a:
OK... 4/9 P = (P*R*R)/100
R = 20/3 = 6 2/3%
The answer is (A).