Adam has 152 stickers.
After
710 of the blue stickers is given away and
another 30 green stickers are bought,
there is an equal number of blue and green stickers.
- How many blue stickers are there in the end?
- How many less green stickers than blue stickers are there at first?
- How many blue stickers are given away?
|
Blue |
Green |
Before |
10 u |
3 u - 30 |
Change |
- 7 u |
+ 30 |
After |
3 u |
3 u |
(a)
Fraction of the blue stickers left
= 1 -
710 =
310 The number of blue stickers and green stickers in the end is the same.
Total number of stickers at first
= 10 u + 3 u - 30
= 13 u - 30
13 u - 30 = 152
13 u = 152 + 30
13 u = 182
1 u = 182 ÷ 13 = 14
Number of blue stickers in the end
= 3 u
= 3 x 14
= 42
(b)
Number of less green stickers than blue stickers at first
= 10 u - (3 u - 30)
= 10 u - 3 u + 30
= 7 u + 30
= 7 x 14 + 30
= 98 + 30
= 128
(c)
Number of blue stickers given away
= 7 u
= 7 x 14
= 98
Answer(s): (a) 42; (b) 128; (c) 98