Question

find the H.C.F of 21, 28, 36, 45.

Answer 1

21=3×7
28=2×2×7
36=2×2×3×3
45=3×3×5

So Highest Common Factor Will Be 1

Answer 2

4521= 1,3,7,21. 28= 1,2,4,7,28. 36= 1,2,3,4,6,12,18,36. 45= 1,3,5,9,15,45. HCF= 1