Adam has 139 stickers.
After
38 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 |
8 u |
5 u - 17 |
Change |
- 3 u |
+ 17 |
After |
5 u |
5 u |
(a)
Fraction of the red stickers left
= 1 -
38 =
58 The number of red stickers and green stickers in the end is the same.
Total number of stickers at first
= 8 u + 5 u - 17
= 13 u - 17
13 u - 17 = 139
13 u = 139 + 17
13 u = 156
1 u = 156 ÷ 13 = 12
Number of red stickers in the end
= 5 u
= 5 x 12
= 60
(b)
Number of less green stickers than red stickers at first
= 8 u - (5 u - 17)
= 8 u - 5 u + 17
= 3 u + 17
= 3 x 12 + 17
= 36 + 17
= 53
(c)
Number of red stickers given away
= 3 u
= 3 x 12
= 36
Answer(s): (a) 60; (b) 53; (c) 36