Adam has 500 red and green stickers.
He buys 60 red stickers and the number of red stickers becomes 3 times as many as green stickers.
- How many more red stickers than green stickers does Adam have at first?
- How many less green stickers than red stickers does Adam have in the end?
|
Red |
Green |
Before |
3 u - 60 |
1 u |
Change |
+ 60 |
No change |
After |
3 u |
1 u |
(a)
The number of green stickers remain unchanged.
Total number of stickers at first
= 1 u + 3 u - 60
= 4 u - 60
4 u - 60 = 500
4 u = 500 + 60
4 u = 560
1 u = 560 ÷ 4 = 140
Number of more red stickers than green stickers at first
= (3 u - 60) - 1 u
= 3 u - 1 u - 60
= 2 u - 60
= 2 x 140 - 60
= 280 - 60
= 220
(b)
Number of less green stickers than red stickers in the end
= 3 u - 1 u
= 2 u
= 2 x 140
= 280
Answer(s): (a) 220; (b) 280