Question

What is the H.C.F. of 4/9, 10/21 and 20/63?
1. 4/189
2. 2/63
3. 6/63
4. None of these

Answer 1

Correct Answer - Option 2 : 2/63

Formula used:

H.C.F of fraction = (H.C.F of numerator/L.C.M of denominator)

Calculation:

Finding the H.C.F of 4, 10 and 20 by prime factorization 

4 → 1 × 2²

10 → 1 × 2 × 5

20 → 1 × 2² × 5

H.C.F of the given number = 2

Finding the L.C.M of 9, 21 and 63 by prime factorization

9 → 1 × 3²

21 → 1 × 3 × 7

63 → 1 × 3² × 7

L.C.M of the given number = 63

H.C.F of the fraction = 2/63

∴ The H.C.F of the given fraction is 2/63