question:In how many different ways can the letters of the word 'PREPTY' be arranged?
Options:
(A) 160
(B) 190
(C) 210
(D) 368
(E) 360
answer:(E)
Stream of consciousness:Number of ways = 61/21 6X5X4X3X2X1 - 360

question:There are 10person among whom 2are brother. The total no.of ways in which these persons can be seated around a round table so that exactly 1person sit between the brothers, is equal to?
Options:
(A) 7!
(B) 7!*2!
(C) 7!*3!
(D) 8!*1!
(E) 8!*4!
answer:(B)
Stream of consciousness:Total number of ways = 7!*2!.

question:Which one of the following is not a prime number?
Options:
(A) 31
(B) 61
(C) 71
(D) 91
(E) 101
answer:
(D)
Stream of consciousness:91 is divisible by 7. So, it is not a prime number.