Short Answer Type
Long Answer TypeShort Answer TypeLong Answer TypeShort Answer TypeFind the LCM and HCF of the following integers by applying the prime factorisation method :
12, 15 and 21
Long Answer TypeUsing prime factorization method, Find the LCM of
(i) 12, 15, 20, 27 (ii) 21, 28, 36, 45.
Since, 12 = 2 × 2 × 3 = 22 × 3
15 = 3 × 5
20 = 2 × 2 × 5 = 22 × 5
and 27 = 3 × 3 × 3 = 33
∴ LCM = Product of each prime factor with highest power
= 22 × 33 × 5 = 540
i.e., LCM (12, 15, 20, 27) = 540.
(ii) 21, 28, 36, 45
Since, 21 = 3 × 7
28 = 2 × 2 × 7 = 22 × 7>
36 = 2 × 2 × 3 × 3 = 22 × 32
and 45 = 5 × 3 × 3 = 5 × 32
∴ LCM = Product of each prime factor with highest power
= 32 × 7 × 22 × 5
= 1260
i.e. LCM (21, 28, 36, 45)= 1260.
Switch
