Adam has 400 red and green stickers.
He sells 40 red stickers and the number of green stickers becomes 3 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 + 40 |
3 u |
Change |
- 40 |
No Change |
After |
1 u |
3 u |
(a)
The number of green stickers remains unchanged.
Total number of stickers at first
= 1 u + 40 + 3 u
= 4 u + 40
4 u + 40 = 400
4 u = 400 - 40
4 u = 360
1 u = 360 ÷ 4 = 90
Number of more green stickers than red stickers at first
= 3 u - (1 u + 40)
= 3 u - 1 u - 40
= 2 u - 40
= 2 x 90 - 40
= 180 - 40
= 140
(b)
Number of less red stickers than green stickers in the end
= 3 u - 1 u
= 2 u
= 2 x 90
= 180
Answer(s): (a) 140; (b) 180