Question

Check the following numbers and see whether each one of them is divisible by 4 or 8?

(a) 1240
(b) 2878
(c) 1604
(d) 2402

Answer 1

A number is divisible by 4 if the number formed by its last 2 digits is divisible by 4
A number is divisible by 8 if the number formed by its last 3 digits is divisible by 8

(a) For 1240,

40 is divisible by 4 because $\frac{40}{4}=10$

So, 1240 is divisible by 4

240 is divisible by 8 because $\frac{240}{8}=30$

Therefore, 1240 is divisible by both 4 and 8

(b) For 2878;

78 is not divisible by 4. So, 2878 is also not divisible by 4

878 form the last 3 digits of 2878. 878 is not divisible by 8. So, 2878 is also not divisible by 8.

(c) For 1604;

604 is not divisible by 8

So, 1604 is not divisible by 8

04 is divisible by 4.

So, 1604 is divisible by 4.

(d) For 2402;

2 is not divisible by 4.

So, 2402 is not divisible by 4

402 is not divisible by 8.

So, 2402 is not divisible by 8.