QUESTION

CSAT

Hard

Maths

Prelims 2025

A natural number N is such that it can be expressed as N=p+q+rN = p + q + r, where p, q, and r are distinct factors of N. How many numbers below 50 have this property?

Select an option to attempt

Explanation

Key idea: If NN is a multiple of 6, then the three distinct proper factors p=N/6p = N/6, q=N/3q = N/3, r=N/2r = N/2 satisfy p+q+r=Np + q + r = N and are all factors of NN.

Hence, every multiple of 6 works. Below 50, the multiples of 6 are: 6, 12, 18, 24, 30, 36, 42, 48 → 8 numbers.

Therefore, the required count is 8.

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