Question

Find the smallest number which when doubled will be exactly divisible by 4, 10, 15

Answer 1

30
Let the number be x
So 2x is divisible by 4,10,15
Divisible means find the LCM of those three numbers which is 60
2x=60
Divide both sides by 2
x=30

Answer 2

60
60:4=15
60:10= 6
60:15= 4