For what value of digit x is :

42x8 divisible by 4 ?

According to the divisibility of 4, if the two digit number formed by its ten's digit and unit digit is divisible by 4 then the number is divisible by 4.

42x8 is divisible by 4

⇒ x8 is divisible by 4

⇒ 10x + 8 is divisible by 4

⇒ 10x + 8 = 8, 28, 48, 68, 88, 108,……………

⇒ 10x = 0, 20, 40, 60, 80, 100,……………

⇒ x = 0, 2, 4, 6, 8, 10,……………

Since x is a digit. So, x = 0, 2, 4, 6 or 8.