Adam has 100 red and green stickers.
He buys 50 red stickers and the number of red stickers becomes 4 times as many as green stickers.
- How many more red stickers than green stickers does Adam have at first?
- How many less green stickers than red stickers does Adam have in the end?
|
Red |
Green |
Before |
4 u - 50 |
1 u |
Change |
+ 50 |
No change |
After |
4 u |
1 u |
(a)
The number of green stickers remain unchanged.
Total number of stickers at first
= 1 u + 4 u - 50
= 5 u - 50
5 u - 50 = 100
5 u = 100 + 50
5 u = 150
1 u = 150 ÷ 5 = 30
Number of more red stickers than green stickers at first
= (4 u - 50) - 1 u
= 4 u - 1 u - 50
= 3 u - 50
= 3 x 30 - 50
= 90 - 50
= 40
(b)
Number of less green stickers than red stickers in the end
= 4 u - 1 u
= 3 u
= 3 x 30
= 90
Answer(s): (a) 40; (b) 90