Adam has 300 green and blue stickers.
He buys 90 green stickers and the number of green stickers becomes 2 times as many as blue stickers.
- How many more green stickers than blue stickers does Adam have at first?
- How many less blue stickers than green stickers does Adam have in the end?
|
Green |
Blue |
Before |
2 u - 90 |
1 u |
Change |
+ 90 |
No change |
After |
2 u |
1 u |
(a)
The number of blue stickers remain unchanged.
Total number of stickers at first
= 1 u + 2 u - 90
= 3 u - 90
3 u - 90 = 300
3 u = 300 + 90
3 u = 390
1 u = 390 ÷ 3 = 130
Number of more green stickers than blue stickers at first
= (2 u - 90) - 1 u
= 2 u - 1 u - 90
= 1 u - 90
= 1 x 130 - 90
= 130 - 90
= 40
(b)
Number of less blue stickers than green stickers in the end
= 2 u - 1 u
= 1 u
= 1 x 130
= 130
Answer(s): (a) 40; (b) 130