Question

9/10,12/25,18/35,21/40=? H.c.l

Answer 1

3/1400

Method-1

HCF of 9, 12, 18, 21 = 3
LCM of 10, 25, 35, 40 = 1400

∴ HCF 9/10, 12/25, 18/35, 21/40 = HCF of numerators / LCM of denominators = 3/1400

Method-2

9/10 = 1260/1400
12/25 = 672/1400
18/35 = 720/1400
21/40 = 735/1400

∴ HCF 9/10, 12/25, 18/35, 21/40 = (HCF of 1260, 672, 720, 735) / 1400 = 3/1400