Question

What 3-digit number has the number 5 as its digit in the tens place and the digit in the hundreds place twice as big as the digit in the ones place?
(Note: There can be multiple solutions)

Answer 1

First, we need to realize that the number has 3 digits and the digit in the middle is 5.
We can represent this number as:
a5b,
where the digit in the hundreds place is a and the digit in the ones place is b.

Now, we try to find combinations of a and b where a is twice the value of b amongst the numbers 0 to 9.

Possible choices for a and b:
a = 8 and b = 4
a = 6 and b = 3
a = 4 and b = 2
a = 2 and b =1

The possible numbers can be 854, 653, 452, or 251