Question

18 is divisible by both 2 and 3. It is also divisible by 2x 3=6

Answer 1

18 is divisible by both 2 and 3. It is also divisible by 2 x 3=6
Actually  for this we can use divisibility condition
According to the divisibility condition
   divisible by 2 ->  numbers end with 0, 2, 4, 6, 8
   divisible by 3 -> the sum of the digits is multiple of 3
   divisible by 6 --> If both condition of 2 & 3 satisfied.
given number 18

18 - > it is divisible by 2 (because end with 8)
     - > it is divisible by 3 (because 1+8 =9 = 3x3)
      -> so, it is divisible by 6