Question

Find the number of pairs of natural numbers with LCM as $56$.

• A. $3$
• B. $4$
• C. $10$
• D. Can't be determined

Answer 1

Answer: (C)

$10$

Let a, b be the two numbers with LCM 56
Since 56 is the LCM a and b will
be the divisors of 56. The divisors of 56 are 1, 2, 4, 7, 8, 14, 28 and
56
Combining two at a time the possible pairs with LCM as 56 are (1,
56), (2, 56), (4, 56), (7, 56), (8, 56), (14, 56), (28, 56), (8, 14),
(8, 28) and (7, 8) Thus in all there are 10 pairs