Adam has 3 times as many blue stickers as green stickers.
After he gives away 20 green stickers,
Adam has 7 times as many blue stickers as green stickers.
- How many more blue stickers than green stickers does Adam have at first?
- How many less green stickers than blue stickers does Adam have in the end?
|
Blue |
Green |
Before |
3 x 7 = 21 u |
1 x 7 = 7 u |
Change |
No Change |
- 20 |
After |
7 x 3 = 21 u |
1 x 3 = 3 u |
(a)
The number of blue stickers remains unchanged.
Make the number of blue stickers and green stickers the same using LCM of 3 and 7.
LCM of 3 and 7 = 21
Number of green stickers that Adam gives away
= 7 u - 3 u
= 4 u
4 u = 20
1 u = 20 ÷ 4 = 5
Number of more blue stickers than green stickers at first
= 21 u - 7 u
= 14 u
= 14 x 5
= 70
(b)
Number of less green stickers than blue stickers in the end
= 21 u - 3 u
= 18 u
= 18 x 5
= 90
Answer(s): (a) 70; (b) 90