Three boxes contain countersThere are 63 counters in totalThe 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 10Work 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.