What is the HCF of 16, 72 and 28?
A3
B4
C2
D1
Answer & Solution
Correct answer: B. 4
1. 16 = 2^4, 72 = 2^3 x 3^2, 28 = 2^2 x 7.
2. The common prime factor is 2, lowest power 2^2 = 4.
3. So HCF = 4.
_Source: RRB Group D CEN-02/2018 PYQ, Q.25._
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