Adam has 600 red and green stickers.
He buys 20 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 - 20 |
1 u |
Change |
+ 20 |
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 - 20
= 5 u - 20
5 u - 20 = 600
5 u = 600 + 20
5 u = 620
1 u = 620 ÷ 5 = 124
Number of more red stickers than green stickers at first
= (4 u - 20) - 1 u
= 4 u - 1 u - 20
= 3 u - 20
= 3 x 124 - 20
= 372 - 20
= 352
(b)
Number of less green stickers than red stickers in the end
= 4 u - 1 u
= 3 u
= 3 x 124
= 372
Answer(s): (a) 352; (b) 372