Adam has 900 red and blue stickers.
He sells 60 red stickers and the number of blue stickers becomes 3 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 + 60 |
3 u |
Change |
- 60 |
No Change |
After |
1 u |
3 u |
(a)
The number of blue stickers remains unchanged.
Total number of stickers at first
= 1 u + 60 + 3 u
= 4 u + 60
4 u + 60 = 900
4 u = 900 - 60
4 u = 840
1 u = 840 ÷ 4 = 210
Number of more blue stickers than red stickers at first
= 3 u - (1 u + 60)
= 3 u - 1 u - 60
= 2 u - 60
= 2 x 210 - 60
= 420 - 60
= 360
(b)
Number of less red stickers than blue stickers in the end
= 3 u - 1 u
= 2 u
= 2 x 210
= 420
Answer(s): (a) 360; (b) 420