Adam has 300 red and green stickers.
He buys 30 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 - 30 |
1 u |
Change |
+ 30 |
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 - 30
= 5 u - 30
5 u - 30 = 300
5 u = 300 + 30
5 u = 330
1 u = 330 ÷ 5 = 66
Number of more red stickers than green stickers at first
= (4 u - 30) - 1 u
= 4 u - 1 u - 30
= 3 u - 30
= 3 x 66 - 30
= 198 - 30
= 168
(b)
Number of less green stickers than red stickers in the end
= 4 u - 1 u
= 3 u
= 3 x 66
= 198
Answer(s): (a) 168; (b) 198