Question

If the division N ÷ 5 leaves a remainder of 4, and the division N ÷ 2 leaves a remainder of 1, then what must be the ones digit of N?
(3 marks)

Answer 1

Solution:

Since N ÷ 5 leaves a remainder 4, so ones digit can be 4 or 9 as 0 + 4 = 4 and 5 + 4 = 9
(1 mark)

Also, since N ÷ 2 leaves a remainder 1, so the ones
digit must be 9 only.
(1 mark)

4 is even number so it will not leave any remainder when it is divided by 2.
(0.5 marks)

Therefore, the digit at ones place of N will be 9.
(0.5 marks)