3 children have a total of 1900 stickers.
Bryan has 3 times as many stickers as Adam.
Charlie has 600 stickers more stickers than Adam.

1. How many stickers do Bryan and Adam have?
2. How many stickers does Adam have less than Bryan?
3. How many stickers does Adam have less than Bryan and Charlie?

(a)
Choose the person with least stickers to be 1 u.

Number of stickers that Adam has = 1 u
Number of stickers that Bryan has = 3 u = 3 u
Number of stickers that Charlie has = 1 u + 600

Total number of stickers
= 1 u + 3 u + 1 u + 600
= 5 u + 600

5 u + 600 = 1900
5 u = 1900 - 600
5 u = 1300

1 u = 1300 ÷ 5 = 260

Number of stickers that Bryan and Adam have
= 3 u + 1 u
= 4 u
= 4 x 260
= 1040

(b)
Number of stickers that Adam has less than Bryan
= 3 u - 1u
= 2 u
= 2 x 260
= 520

(c)
Number of stickers that Adam has less than Bryan and Charlie
= (3 u + 1 u + 600) - 1 u
= 3 u + 600
= 3 x 260 + 600
= 780 + 600
= 1380

Answer(s); (a) 1040; (b) 520; (c) 1380