Question

In a colony of 100 blocks of flats numbering 1 to 100, a school van
stops at every sixth block while a school bus stops at every tenth
block. On which stops will both of them stop if they start from the
entrance of the colony?

Answer 1

The stop on which the both bus stops;
= LCM of 6 & 10
6 = 2×3
10 = 2×5

LCM = 2×3×5
= 30
the other stops will be multiple of 30
= 60 & 90

hence the answer is 30th,60th & 90th block stop

hope this helped you ..............!

Answer 2

The blocks at which both vans will stop are:30,60,90