Adam has 300 red and blue stickers.
He sells 30 red stickers and the number of blue stickers becomes 2 times as many as red stickers.
- How many more blue stickers than red stickers does Adam have at first?
- How many less red stickers than blue stickers does Adam have in the end?
|
Red |
Blue |
Before |
1 u + 30 |
2 u |
Change |
- 30 |
No Change |
After |
1 u |
2 u |
(a)
The number of blue stickers remains unchanged.
Total number of stickers at first
= 1 u + 30 + 2 u
= 3 u + 30
3 u + 30 = 300
3 u = 300 - 30
3 u = 270
1 u = 270 ÷ 3 = 90
Number of more blue stickers than red stickers at first
= 2 u - (1 u + 30)
= 2 u - 1 u - 30
= 1 u - 30
= 1 x 90 - 30
= 90 - 30
= 60
(b)
Number of less red stickers than blue stickers in the end
= 2 u - 1 u
= 1 u
= 1 x 90
= 90
Answer(s): (a) 60; (b) 90