Adam has 118 stickers.
After
25 of the red stickers is given away and
another 10 blue stickers are bought,
there is an equal number of red and blue stickers.
- How many red stickers are there in the end?
- How many less blue stickers than red stickers are there at first?
- How many red stickers are given away?
|
Red |
Blue |
Before |
5 u |
3 u - 10 |
Change |
- 2 u |
+ 10 |
After |
3 u |
3 u |
(a)
Fraction of the red stickers left
= 1 -
25 =
35 The number of red stickers and blue stickers in the end is the same.
Total number of stickers at first
= 5 u + 3 u - 10
= 8 u - 10
8 u - 10 = 118
8 u = 118 + 10
8 u = 128
1 u = 128 ÷ 8 = 16
Number of red stickers in the end
= 3 u
= 3 x 16
= 48
(b)
Number of less blue stickers than red stickers at first
= 5 u - (3 u - 10)
= 5 u - 3 u + 10
= 2 u + 10
= 2 x 16 + 10
= 32 + 10
= 42
(c)
Number of red stickers given away
= 2 u
= 2 x 16
= 32
Answer(s): (a) 48; (b) 42; (c) 32