Let A = 1, 2, 3, …, 20 . Let R_1 and R_2 two relation on A such that R_1 = (a, b) : b is divisible by a , R_2...

Question

Let A = 1, 2, 3, …, 20 . Let R_1 and R_2 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 ____.

Accepted Answer

46

JEE Main 2024 Mathematics question

Solution