Adam has 400 blue and red stickers.
He buys 50 blue stickers and the number of blue stickers becomes 4 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 |
4 u - 50 |
1 u |
Change |
+ 50 |
No change |
After |
4 u |
1 u |
(a)
The number of red stickers remain unchanged.
Total number of stickers at first
= 1 u + 4 u - 50
= 5 u - 50
5 u - 50 = 400
5 u = 400 + 50
5 u = 450
1 u = 450 ÷ 5 = 90
Number of more blue stickers than red stickers at first
= (4 u - 50) - 1 u
= 4 u - 1 u - 50
= 3 u - 50
= 3 x 90 - 50
= 270 - 50
= 220
(b)
Number of less red stickers than blue stickers in the end
= 4 u - 1 u
= 3 u
= 3 x 90
= 270
Answer(s): (a) 220; (b) 270