Adam has 41 stickers.
After
37 of the red stickers is given away and
another 14 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 |
7 u |
4 u - 14 |
Change |
- 3 u |
+ 14 |
After |
4 u |
4 u |
(a)
Fraction of the red stickers left
= 1 -
37 =
47 The number of red stickers and blue stickers in the end is the same.
Total number of stickers at first
= 7 u + 4 u - 14
= 11 u - 14
11 u - 14 = 41
11 u = 41 + 14
11 u = 55
1 u = 55 ÷ 11 = 5
Number of red stickers in the end
= 4 u
= 4 x 5
= 20
(b)
Number of less blue stickers than red stickers at first
= 7 u - (4 u - 14)
= 7 u - 4 u + 14
= 3 u + 14
= 3 x 5 + 14
= 15 + 14
= 29
(c)
Number of red stickers given away
= 3 u
= 3 x 5
= 15
Answer(s): (a) 20; (b) 29; (c) 15