Adam has 40 more stickers than Charlie.
After Charlie gives away 20 stickers,
Adam has 5 times as many stickers as Charlie.

1. How many stickers does Charlie have at first?
2. How many stickers does Adam have?
3. How many stickers do they have altogether at first?
4. How many stickers do they have altogether in the end?

	Adam	Charlie
Before	1 u + 20 + 40	1 u + 20
Change	No change	- 20
After	5 u	1 u

(a)
The number of stickers that Adam has at first and in the end remains unchanged.
Number of stickers that Adam has at first = Number of stickers that Adam has in the end

1 u + 20 + 40 = 5 u
1 u + 60 = 5 u
5 u - 1 u = 60
4 u = 60

1 u = 60 ÷ 4 = 15

Number of stickers that Charlie has
= 1 u + 20
= 15 + 20
= 35

(b)
Number of stickers that Adam has
= 5 u
= 5 x 15
= 75

(c)
Number of stickers that they have altogether at first
= 1 u + 20 + 40 + 1 u + 20
= 1 u + 1 u + 20 + 40 + 20
= 2 u + 80
= 2 x 15 + 80
= 30 + 80
= 110

(d)
Number of stickers that they have altogether in the end
= 5 u + 1 u
= 6 u
= 6 x 15
= 90

Answer(s): (a) 35; (b) 75; (c) 110; (d) 90