Adam has 500 red and green stickers.
He sells 80 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 + 80 |
2 u |
Change |
- 80 |
No Change |
After |
1 u |
2 u |
(a)
The number of green stickers remains unchanged.
Total number of stickers at first
= 1 u + 80 + 2 u
= 3 u + 80
3 u + 80 = 500
3 u = 500 - 80
3 u = 420
1 u = 420 ÷ 3 = 140
Number of more green stickers than red stickers at first
= 2 u - (1 u + 80)
= 2 u - 1 u - 80
= 1 u - 80
= 1 x 140 - 80
= 140 - 80
= 60
(b)
Number of less red stickers than green stickers in the end
= 2 u - 1 u
= 1 u
= 1 x 140
= 140
Answer(s): (a) 60; (b) 140