Fundamentholfundamenthol
JEE Main2026Apr 2, Shift 2Mathematics
Q.

Let . Let be a relation on the set given by if and only if divides and . Then the number of elements in is ______.

Solution

Count divisibility pairs with and :

: pairs. : pairs. : . : . : .

Total divisibility pairs .

Count pairs with : for each fixed , ranges over . Summing: .

By independence, .

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