Adam has 3 times as many blue stickers as red stickers.
After he gives away 20 red stickers,
Adam has 5 times as many blue stickers 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 |
3 x 5 = 15 u |
1 x 5 = 5 u |
Change |
No Change |
- 20 |
After |
5 x 3 = 15 u |
1 x 3 = 3 u |
(a)
The number of blue stickers remains unchanged.
Make the number of blue stickers and red stickers the same using LCM of 3 and 5.
LCM of 3 and 5 = 15
Number of red stickers that Adam gives away
= 5 u - 3 u
= 2 u
2 u = 20
1 u = 20 ÷ 2 = 10
Number of more blue stickers than red stickers at first
= 15 u - 5 u
= 10 u
= 10 x 10
= 100
(b)
Number of less red stickers than blue stickers in the end
= 15 u - 3 u
= 12 u
= 12 x 10
= 120
Answer(s): (a) 100; (b) 120