66. 1ff(n) is a mutiplicative function and f (n)= d,then f is: (a) multiplicative (b) multiplicative inverse (c) gaussian (d) none of these 67. for any positive

66. 1ff(n) is a mutiplicative function and F (n)= d,then f is: (A) multiplicative (B) multiplicative inverse (C) Gaussian (D) None of these 67. For any positive integer n. j (), u (n + De(n+2)u(e+3) is cqual to : (A) 0 (B) 1 (C) tn (D) None of these 68. For any positive integer n, (n). if and only if n is prime. A)t1 (B)-1 (C)nt1 (D) None of these 69. Ifn is a .. number, then the smallest prime divisor of n is s n. (A) prime (B) composite (C) odd prime (D) None of these 70. Ifa=b(mod m), a = b(mod ) and k (m, n), then (A) a-b (mod n) (B) a = bmod m) (C) a-b (mod k) (D) Nonc of these 71. Let a, b and c be integers with not both a and b equal to 0 and let g - g.c.d. (a, 6). if głe, then the equation ax +by c has.. S0lutions in integers. (B) finite (A) unique (D) None of these (C) no 72. If a b (mod m); a, = b, (mod m), then (B) a- a, = b -b, (mod m) (A) a t+ a = by + b (mod m) (D) Nonc of these (C) Both (A) and (B) (13)