Adam has 900 red and green stickers.
He sells 90 red stickers and the number of green stickers becomes 2 times as many as red stickers.
- How many more green stickers than red stickers does Adam have at first?
- How many less red stickers than green stickers does Adam have in the end?
|
Red |
Green |
Before |
1 u + 90 |
2 u |
Change |
- 90 |
No Change |
After |
1 u |
2 u |
(a)
The number of green stickers remains unchanged.
Total number of stickers at first
= 1 u + 90 + 2 u
= 3 u + 90
3 u + 90 = 900
3 u = 900 - 90
3 u = 810
1 u = 810 ÷ 3 = 270
Number of more green stickers than red stickers at first
= 2 u - (1 u + 90)
= 2 u - 1 u - 90
= 1 u - 90
= 1 x 270 - 90
= 270 - 90
= 180
(b)
Number of less red stickers than green stickers in the end
= 2 u - 1 u
= 1 u
= 1 x 270
= 270
Answer(s): (a) 180; (b) 270