Find the invalid no.from the following series 13, 18, 25, 30, 37, 40
Options:
(A) 23
(B) 26
(C) 40
(D) 42
(E) 49

The differences between two successive terms from the beginning are 7, 5, 7, 5, 7, 5. So, 40 is wrong. So the answer is: (C).

A train 70 m long, running with a speed of 63 km/hr will pass a tree in?
Options:
(A) 140 sec
(B) 160 sec
(C) 176 sec
(D) 150 sec
(E) 170 sec

Speed = 63 * 5/18 = 35/2 m/sec
Time taken = 70 * 2/35 = 140 sec So the answer is: (A).

A train 260 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
Options:
(A) 40
(B) 32
(C) 26
(D) 21
(E) 14

Speed = 45 * 5/18 = 25/2 m/sec
Total distance covered = 260 + 140 = 400 m
Required time = 400 * 2/25 = 32 sec So the answer is: (B).

The edges of cuboid are 4 cm; 5 cm and 6 cm. Find its surface area?
Options:
(A) 228
(B) 148
(C) 992
(D) 772
(E) 222
2(4*5 + 5*6 + 4*6) = 148 So the answer is: (B).