Adam has 600 blue and red stickers.
He buys 30 blue stickers and the number of blue stickers becomes 2 times as many as red stickers.
- How many more blue stickers than red stickers does Adam have at first?
- How many less red stickers than blue stickers does Adam have in the end?
|
Blue |
Red |
Before |
2 u - 30 |
1 u |
Change |
+ 30 |
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 - 30
= 3 u - 30
3 u - 30 = 600
3 u = 600 + 30
3 u = 630
1 u = 630 ÷ 3 = 210
Number of more blue stickers than red stickers at first
= (2 u - 30) - 1 u
= 2 u - 1 u - 30
= 1 u - 30
= 1 x 210 - 30
= 210 - 30
= 180
(b)
Number of less red stickers than blue stickers in the end
= 2 u - 1 u
= 1 u
= 1 x 210
= 210
Answer(s): (a) 180; (b) 210