Adam has 200 green and red stickers.
He buys 40 green 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?
|
Green |
Red |
Before |
2 u - 40 |
1 u |
Change |
+ 40 |
No change |
After |
2 u |
1 u |
(a)
The number of red stickers remain unchanged.
Total number of stickers at first
= 1 u + 2 u - 40
= 3 u - 40
3 u - 40 = 200
3 u = 200 + 40
3 u = 240
1 u = 240 ÷ 3 = 80
Number of more green stickers than red stickers at first
= (2 u - 40) - 1 u
= 2 u - 1 u - 40
= 1 u - 40
= 1 x 80 - 40
= 80 - 40
= 40
(b)
Number of less red stickers than green stickers in the end
= 2 u - 1 u
= 1 u
= 1 x 80
= 80
Answer(s): (a) 40; (b) 80