Adam has 178 stickers.
After
38 of the blue stickers is given away and
another 30 red stickers are bought,
there is an equal number of blue and red stickers.
- How many blue stickers are there in the end?
- How many less red stickers than blue stickers are there at first?
- How many blue stickers are given away?
|
Blue |
Red |
Before |
8 u |
5 u - 30 |
Change |
- 3 u |
+ 30 |
After |
5 u |
5 u |
(a)
Fraction of the blue stickers left
= 1 -
38 =
58 The number of blue stickers and red stickers in the end is the same.
Total number of stickers at first
= 8 u + 5 u - 30
= 13 u - 30
13 u - 30 = 178
13 u = 178 + 30
13 u = 208
1 u = 208 ÷ 13 = 16
Number of blue stickers in the end
= 5 u
= 5 x 16
= 80
(b)
Number of less red stickers than blue stickers at first
= 8 u - (5 u - 30)
= 8 u - 5 u + 30
= 3 u + 30
= 3 x 16 + 30
= 48 + 30
= 78
(c)
Number of blue stickers given away
= 3 u
= 3 x 16
= 48
Answer(s): (a) 80; (b) 78; (c) 48