could someone please tell me the answer of the 13th question..

uiv Ihtegers have if R is a) a, b) l a> b 4950b) ((a, b) l a t b? c) {(a, b) l a = b + 1 }.ml) {(a, b) | a = 1 }? e) {(a, b) | a b-1 }, 0.) How many nonzero entries does the matrix re the relation R on A = { 1, 2, 3,._1000) consis first 1000 positive integers have if R is a) {(a, b) la500,50 b) {(a, b) la c) {(a, b) | a + b = 1000) ?aaa d) {(a, b) la + b