84. a positive integer is divisible by 9 iff the sum of the digits in is decima! represontation is divisible by: (4) 3 cb) )9 (c) 81 (d) none of these 85. fp is

84. A positive integer is divisible by 9 iff the sum of the digits in is decima! represontation is divisible by: (4) 3 CB) )9 (C) 81 (D) None of these 85. fp is n peime and a be any integer such that pia. Then the solution o ear oongruence ax wb(mod p) is given by: (A)ra mod p (B) *p mod a (C) aP modp (D None of these 86. The integer p is prime if and only if: LP-1--D(mod p) 1P-1= #1 (mod p) (B) p-11(mad p) (D) None of these 8. Lel p be a s na n e ny integer, then -1y"(mod p). 2p (A) prime, positive (B) odd, positive (C) odd, negative (D) None of these 88. The quodratie congruence x = -I(mod p). p 1s a has a solution if p-1(mod 4). (A) composite (B) prime (C)perfect (D) None of these 89. Ifn is not divisible by any prime S vn. then n is a'an (A) Even (B) Odd (C) Prime (D) None of these ( 16) FIM 3-MAT(8)8