Adam has 198 stickers.
After
47 of the green stickers is given away and
another 12 blue stickers are bought,
there is an equal number of green and blue stickers.
- How many green stickers are there in the end?
- How many less blue stickers than green stickers are there at first?
- How many green stickers are given away?
|
Green |
Blue |
Before |
7 u |
3 u - 12 |
Change |
- 4 u |
+ 12 |
After |
3 u |
3 u |
(a)
Fraction of the green stickers left
= 1 -
47 =
37 The number of green stickers and blue stickers in the end is the same.
Total number of stickers at first
= 7 u + 3 u - 12
= 10 u - 12
10 u - 12 = 198
10 u = 198 + 12
10 u = 210
1 u = 210 ÷ 10 = 21
Number of green stickers in the end
= 3 u
= 3 x 21
= 63
(b)
Number of less blue stickers than green stickers at first
= 7 u - (3 u - 12)
= 7 u - 3 u + 12
= 4 u + 12
= 4 x 21 + 12
= 84 + 12
= 96
(c)
Number of green stickers given away
= 4 u
= 4 x 21
= 84
Answer(s): (a) 63; (b) 96; (c) 84