Adam has 143 stickers.
After
79 of the green stickers is given away and
another 22 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 |
9 u |
2 u - 22 |
Change |
- 7 u |
+ 22 |
After |
2 u |
2 u |
(a)
Fraction of the green stickers left
= 1 -
79 =
29 The number of green stickers and red stickers in the end is the same.
Total number of stickers at first
= 9 u + 2 u - 22
= 11 u - 22
11 u - 22 = 143
11 u = 143 + 22
11 u = 165
1 u = 165 ÷ 11 = 15
Number of green stickers in the end
= 2 u
= 2 x 15
= 30
(b)
Number of less red stickers than green stickers at first
= 9 u - (2 u - 22)
= 9 u - 2 u + 22
= 7 u + 22
= 7 x 15 + 22
= 105 + 22
= 127
(c)
Number of green stickers given away
= 7 u
= 7 x 15
= 105
Answer(s): (a) 30; (b) 127; (c) 105