Question

A school bus picking up children in a colony of flats stops at every sixth block of flats. Another school bus starting from the same place stops at every eighth blocks of flats. Which is the first bus stop at which both of them will stop?

Answer 1

First bus stop at which both the buses will stop together = LCM of 6th block and 8th block

Prime factorisation of 6 = 2 × 3
Prime factorisation of 8 = 2 × 2 × 2
∴ Required LCM = 2 × 2 × 2 × 3 = 24
Hence, the first bus stop at which both the buses will stop together will be at the 24th block.