The smallest number that is divisible by 2,4,6 is____

The correct option is B 12

The smallest number divisible by any 2 or more numbers is their least common multiple (LCM).
The multiples of 2 : 2 , 4 , 6 , 8 , 10 , 12 , 14 .....
The multiples of 4: 4 , 8 , 12 , 16 , 20 ......
The multiples of 6: 6 , 12 , 18 , 24 .........
As you can see, 12 is the smallest multiple that is commom for all 3 numbers.
So, the LCM of 2, 4, 6 = 12