Question

Let's find H.C.F. and L.C.M. of the following numbers.by short division methods (d) 28, 49, 70​

Answer 1

ANSWERS

H.C.F = 7 , L.C.M. = 980

EXPLANATION ( HCF )

For H.C.F. first we should find the product of the smallest power of each prime factor in the numbers.

SO, BY PRIME FACTORISATION

28 = 2 × 2 × 7 = 2^2 × 7 (^means square)

49 = 7 × 7 = 7^2

70 = 2 × 5 × 7

H.C.F( 28, 49, 70 ) = 7

L.C.M.

For L.C.M. we need to take the product of the greatest power of each prime factor involved in the numbers. So,

L.C.M(28, 49, 70) = 7^2 × 2^ 2 × 5

= 280