Adam has 100 red and blue stickers.
He buys 40 red stickers and the number of red stickers becomes 4 times as many as blue stickers.
- How many more red stickers than blue stickers does Adam have at first?
- How many less blue stickers than red stickers does Adam have in the end?
|
Red |
Blue |
Before |
4 u - 40 |
1 u |
Change |
+ 40 |
No change |
After |
4 u |
1 u |
(a)
The number of blue stickers remain unchanged.
Total number of stickers at first
= 1 u + 4 u - 40
= 5 u - 40
5 u - 40 = 100
5 u = 100 + 40
5 u = 140
1 u = 140 ÷ 5 = 28
Number of more red stickers than blue stickers at first
= (4 u - 40) - 1 u
= 4 u - 1 u - 40
= 3 u - 40
= 3 x 28 - 40
= 84 - 40
= 44
(b)
Number of less blue stickers than red stickers in the end
= 4 u - 1 u
= 3 u
= 3 x 28
= 84
Answer(s): (a) 44; (b) 84