Question

Which of the following numbers are divisible by 3?
(a) 186 (b) 3663
[2 marks]

Answer 1

(a) Sum of the digits of 186 is
= 1 + 8 + 6 = 15
[0.5 mark]
So, 15 is divisible by 3.
Hence 186 is divisible by 3
[0.5 mark]

(b) Sum of the digits of 3663 is
= 3 + 6 + 6 + 3 = 18
[0.5 mark]
So, 18 is divisible by 3.
Hence 3663 is divisible by 3
[0.5 mark]