Answer:
see explanation
Explanation:
(b)
18 = 2 × 3 × 3 = 2 × 3²
15 = 3 × 5
The common prime factor = 3
HCF = 3
(c)
16 = 2 × 2 × 2 × 2 =

32 = 2 × 2 × 2 × 2 × 2 =

48 = 2 × 2 × 2 × 2 × 3 =
× 3
The common prime factor =

HCF =
= 16
(e)
27 = 3 × 3 × 3 = 3³
63 = 3 × 3 × 7 = 3² × 7
54 = 2 × 3 × 3 × 3 = 2 × 3³
The common prime factor = 3²
HCF = 3² = 9