the smallest integer which is an exact multiple of both 60 and 126

Answer 1

60=2^2*3*5
126=2*3^2*7
The LCM is therefore
LCM=2^2*3^2*5*7
=1260

Alternatively you find it by division:

2 | 60, 126
3 | 30, 63
1 | 10, 21

LCM = 2*3*1*10*21 = 1260

Answer 2

It should be 3 instead of 2 in first answer