Adam has 900 blue and red stickers.
He buys 30 blue 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?
|
Blue |
Red |
Before |
5 u - 30 |
1 u |
Change |
+ 30 |
No change |
After |
5 u |
1 u |
(a)
The number of red stickers remain unchanged.
Total number of stickers at first
= 1 u + 5 u - 30
= 6 u - 30
6 u - 30 = 900
6 u = 900 + 30
6 u = 930
1 u = 930 ÷ 6 = 155
Number of more blue stickers than red stickers at first
= (5 u - 30) - 1 u
= 5 u - 1 u - 30
= 4 u - 30
= 4 x 155 - 30
= 620 - 30
= 590
(b)
Number of less red stickers than blue stickers in the end
= 5 u - 1 u
= 4 u
= 4 x 155
= 620
Answer(s): (a) 590; (b) 620