Adam has 169 stickers.
After
25 of the blue stickers is given away and
another 31 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 |
5 u |
3 u - 31 |
Change |
- 2 u |
+ 31 |
After |
3 u |
3 u |
(a)
Fraction of the blue stickers left
= 1 -
25 =
35 The number of blue stickers and red stickers in the end is the same.
Total number of stickers at first
= 5 u + 3 u - 31
= 8 u - 31
8 u - 31 = 169
8 u = 169 + 31
8 u = 200
1 u = 200 ÷ 8 = 25
Number of blue stickers in the end
= 3 u
= 3 x 25
= 75
(b)
Number of less red stickers than blue stickers at first
= 5 u - (3 u - 31)
= 5 u - 3 u + 31
= 2 u + 31
= 2 x 25 + 31
= 50 + 31
= 81
(c)
Number of blue stickers given away
= 2 u
= 2 x 25
= 50
Answer(s): (a) 75; (b) 81; (c) 50