Adam has 98 stickers.
After
710 of the red stickers is given away and
another 19 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 |
10 u |
3 u - 19 |
Change |
- 7 u |
+ 19 |
After |
3 u |
3 u |
(a)
Fraction of the red stickers left
= 1 -
710 =
310 The number of red stickers and blue stickers in the end is the same.
Total number of stickers at first
= 10 u + 3 u - 19
= 13 u - 19
13 u - 19 = 98
13 u = 98 + 19
13 u = 117
1 u = 117 ÷ 13 = 9
Number of red stickers in the end
= 3 u
= 3 x 9
= 27
(b)
Number of less blue stickers than red stickers at first
= 10 u - (3 u - 19)
= 10 u - 3 u + 19
= 7 u + 19
= 7 x 9 + 19
= 63 + 19
= 82
(c)
Number of red stickers given away
= 7 u
= 7 x 9
= 63
Answer(s): (a) 27; (b) 82; (c) 63