Adam has 149 stickers.
After
57 of the green stickers is given away and
another 40 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 - 40 |
Change |
- 5 u |
+ 40 |
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 - 40
= 9 u - 40
9 u - 40 = 149
9 u = 149 + 40
9 u = 189
1 u = 189 ÷ 9 = 21
Number of green stickers in the end
= 2 u
= 2 x 21
= 42
(b)
Number of less red stickers than green stickers at first
= 7 u - (2 u - 40)
= 7 u - 2 u + 40
= 5 u + 40
= 5 x 21 + 40
= 105 + 40
= 145
(c)
Number of green stickers given away
= 5 u
= 5 x 21
= 105
Answer(s): (a) 42; (b) 145; (c) 105