Adam has 136 stickers.
After
58 of the red stickers is given away and
another 7 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 |
8 u |
3 u - 7 |
Change |
- 5 u |
+ 7 |
After |
3 u |
3 u |
(a)
Fraction of the red stickers left
= 1 -
58 =
38 The number of red stickers and green stickers in the end is the same.
Total number of stickers at first
= 8 u + 3 u - 7
= 11 u - 7
11 u - 7 = 136
11 u = 136 + 7
11 u = 143
1 u = 143 ÷ 11 = 13
Number of red stickers in the end
= 3 u
= 3 x 13
= 39
(b)
Number of less green stickers than red stickers at first
= 8 u - (3 u - 7)
= 8 u - 3 u + 7
= 5 u + 7
= 5 x 13 + 7
= 65 + 7
= 72
(c)
Number of red stickers given away
= 5 u
= 5 x 13
= 65
Answer(s): (a) 39; (b) 72; (c) 65