Question

which of the following is the pair of coprimes ? a) 15,5 b) 2,20 c) 15,16 d) 3,12​

Answer 1

(18,25)

If the H.C.F of two numbers are 1 they are said to be co-prime

Factors of 14=1,2,7

Factors of 35=1,5,7

⇒ Common factor =1,7

∴  (14,35) is not pair of co-prime.

Factors of 18=1,2,3,6,9

Factors of 25=1,5

⇒ Common factor =1

∴  (18,25) is pair of co-prime.

Factors of 31=1,31

Factors of 93=1,3,31

⇒ Common factor =1,31

∴  (31,93) is not pair of co-prime.

Factors of 32=1,2,4,8,16

Factors of 62=1,2,31

⇒ Common factor =1,2

∴  (32,62) is not pair of co-prime.