Let A = { 1,2,3,...,20}. Let R_{1} and R_{2} be two relation on A such that R_{1} = {(a,b):b is divisible by a} R_{2} = {(a,b):a is an integral multiple of b} Then, number of elements in R_{1} - R_{2} is equal to: Relation (Mathematics) Question | DivineJEE

Let A = { 1,2,3,...,20}. Let R_{1} and R_{2} be two relation on A such that R_{1} = {(a,b):b is divisible by a} R_{2} = {(a,b):a is an integral multiple of b} Then, number of elements in R_{1} - R_{2} is equal to: Relation (Mathematics) Question | DivineJEE | divineJEE