Using the prime factor method to find L.C.M:
Express the given numbers as a product of prime factors as follows:
30=2×3×5
12=2×2×3
L.C.M = Product of all prime factors with highest number of instances of each factor.
Here, the prime factors are 2, 3 and 5.
3 and 5 occur once in the prime factorisation, while 2 occurs twice. Therfore, we multiply : ( 2 × 2 ) × 3 × 5
Required L.C.M = 2×2 × 3 × 5 = 60