Question

Chen uses these digit cards.

5,6,9
She makes a 2-digit number and a 1-digit number.
She multiplies them together.
Her answer is a multiple of 10

What could Chens multiplication be?

_ _X_

Answer 1

95 x 6

or 96 x 5

Explanation:

Solve by logic

If you examine the three numbers, you will see that 5 is the only factor of 10.

If we multiply 5 by an even number, we get a multiple of 10.

If we multiply 5 by an odd number, we get a multiple of 5.

Therefore, the 1-digit number must be 5 or 6, and the last digit of the 2-digit number must be 6 or 5.

This means that the first digit of the 2-digit number has to be 9.

So the options are: 95 x 6 and 96 x 5

Proof

56 x 9 = 504

59 x 6 = 354

65 x 9 = 585

69 x 5 = 345

95 x 6 = 570

96 x 5 = 480

**Mulitples of 10 have a zero in the units place**