Q: In how many different ways can the letters of the word 'EXTENT' be arranged?
Options:
(A) 250
(B) 180
(C) 300
(D) 310
(E) 360
A: OK... Stream of consciousness: Number of ways = 6!/2!2! = 6X5X4X3X2X1/2X1X2X1 = 180
The answer is (B).

Q: 60 is increased by 50%. Find the final number.
Options:
(A) 100
(B) 110
(C) 90
(D) 30
(E) 160
A: OK... Stream of consciousness: Final number = Initial number + 50%(original number) = 60 + 50%(60) = 60 + 30 = 90.
The answer is (C).

Q: A train 510 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) 52
(C) 26
(D) 21
(E) 14
A: OK... Stream of consciousness: Speed = 45 * 5/18 = 25/2 m/sec
Total distance covered = 510 + 140 = 650 m
Required time = 650 * 2/25 = 52 sec
The answer is (B).

Q: A wheel rotates 20 times every minute and moves 15 cm during each rotation. How many metres does the wheel move in one hour?
Options:
(A) 6 metre
(B) 18 metre
(C) 180 metre
(D) 1200 metre
(E) 130 metre
A:
OK... Stream of consciousness: Number of times wheel moves in 1 hour = 12 * 60 = 1200
:. Distance moves = (1200*15) cms = 18000 cms
In metres = 180 metre
The answer is (C).