Question

find the greatest number which when divided 20,25 and 40 exactly

Answer 1

We need to find HCF of these 3 numbers

20 = 5 × 2²
25 = 5²
40 = 5 × 2³

HCF is 5

5 is the greatest number which can divide 20,25 & 40 exactly.

Answer 2

5
20=5×4
25=5×5
40=5×2×2×2

=5