Three boxes contain counters

There are 63 counters in total

The total number of counters in box A and box B is 36.

The difference between the number of counters in box A and box C is 10

Work out the number of counters in each box.

What we Know: 3 box have some counters. There are 63 counters when they are all combined.

A and B counters = 36

The difference between A and C is 10.

Since we already know A and B we can subtract them from 63 to get C

C = 63 - 36 = 27

Now we have to find A by looking for what number gives us the difference of 10 when subtracted from C.

36 = 18 + 18 or 19 + 17

18 and 18 wont work because it does not give us the difference of 10.

So A = 17 counters and B = 19 counters.