Adam has 800 red and blue stickers.
He sells 20 red stickers and the number of blue stickers becomes 5 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?
|
Red |
Blue |
Before |
1 u + 20 |
5 u |
Change |
- 20 |
No Change |
After |
1 u |
5 u |
(a)
The number of blue stickers remains unchanged.
Total number of stickers at first
= 1 u + 20 + 5 u
= 6 u + 20
6 u + 20 = 800
6 u = 800 - 20
6 u = 780
1 u = 780 ÷ 6 = 130
Number of more blue stickers than red stickers at first
= 5 u - (1 u + 20)
= 5 u - 1 u - 20
= 4 u - 20
= 4 x 130 - 20
= 520 - 20
= 500
(b)
Number of less red stickers than blue stickers in the end
= 5 u - 1 u
= 4 u
= 4 x 130
= 520
Answer(s): (a) 500; (b) 520