Adam has 158 stickers.
After
35 of the red stickers is given away and
another 17 green stickers are bought,
there is an equal number of red and green stickers.
- How many red stickers are there in the end?
- How many less green stickers than red stickers are there at first?
- How many red stickers are given away?
|
Red |
Green |
Before |
5 u |
2 u - 17 |
Change |
- 3 u |
+ 17 |
After |
2 u |
2 u |
(a)
Fraction of the red stickers left
= 1 -
35 =
25 The number of red stickers and green stickers in the end is the same.
Total number of stickers at first
= 5 u + 2 u - 17
= 7 u - 17
7 u - 17 = 158
7 u = 158 + 17
7 u = 175
1 u = 175 ÷ 7 = 25
Number of red stickers in the end
= 2 u
= 2 x 25
= 50
(b)
Number of less green stickers than red stickers at first
= 5 u - (2 u - 17)
= 5 u - 2 u + 17
= 3 u + 17
= 3 x 25 + 17
= 75 + 17
= 92
(c)
Number of red stickers given away
= 3 u
= 3 x 25
= 75
Answer(s): (a) 50; (b) 92; (c) 75