Adam has 142 stickers.
After
57 of the green stickers is given away and
another 38 red stickers are bought,
there is an equal number of green and red stickers.
- How many green stickers are there in the end?
- How many less red stickers than green stickers are there at first?
- How many green stickers are given away?
|
Green |
Red |
Before |
7 u |
2 u - 38 |
Change |
- 5 u |
+ 38 |
After |
2 u |
2 u |
(a)
Fraction of the green stickers left
= 1 -
57 =
27 The number of green stickers and red stickers in the end is the same.
Total number of stickers at first
= 7 u + 2 u - 38
= 9 u - 38
9 u - 38 = 142
9 u = 142 + 38
9 u = 180
1 u = 180 ÷ 9 = 20
Number of green stickers in the end
= 2 u
= 2 x 20
= 40
(b)
Number of less red stickers than green stickers at first
= 7 u - (2 u - 38)
= 7 u - 2 u + 38
= 5 u + 38
= 5 x 20 + 38
= 100 + 38
= 138
(c)
Number of green stickers given away
= 5 u
= 5 x 20
= 100
Answer(s): (a) 40; (b) 138; (c) 100