Answer:
20 sweets.
Step-by-step-explanation:
Let Colin have x sweets.
The Henry gets x+15 sweets
Then according to the ratios:
5/2 = x+15/x
5x = 2x + 30
3x = 30
x = 10.
So Colin has 10 sweets.
The ratio of Brian's sweets to Colin's sweets is 4: 2 or 2:1.
So Brian has 2 * 10 = 20 sweets.