From the set of numbers x, y, t, z, p, q, r and w, how many different combinations can we have without the t,p,q and r in them? Ex:. (x,y), (x), (w,z,y,x), etc and (x,y)=(y,x)
Options:
(A) 10
(B) 12
(C) 15
(D) 16
(E) 30

Another way: Any letter (x, y, z, w) can be included or not. So, we have 2^4 combinations - 4 empty combination = 12 combinations So the answer is: (B).

What amount does Kiran get if he invests Rs. 18000 at 15% p.a. simple interest for four years?
Options:
(A) 228777
(B) 26788
(C) 26088
(D) 28800
(E) 67881

Simple interest = (18000 * 4 * 15)/100 = Rs. 10800
Amount = P + I = 18000 + 10800 = Rs. 28800 So the answer is: (D).

A train 70 m long, running with a speed of 63 km/hr will pass a tree in?
Options:
(A) 4 sec
(B) 16 sec
(C) 6 sec
(D) 20 sec
(E) 8 sec

Speed = 63 * 5/18 = 35/2 m/sec
Time taken = 70 * 2/35 = 16 sec So the answer is: (A).

A can do a piece of work in 14 days. When he had worked for 2 days B joins him. If the complete work was finished in 8 days. In how many days B alone can finish the work?
Options:
(A) 18
(B) 77
(C) 66
(D) 55
(E) 14
8/14 + 6/x = 1
X = 14 days So the answer is: (E).