Adam has 5 times as many green stickers as red stickers.
After he gives away 20 red stickers,
Adam has 7 times as many green stickers as red stickers.
- How many more green stickers than red stickers does Adam have at first?
- How many less red stickers than green stickers does Adam have in the end?
|
Green |
Red |
Before |
5 x 7 = 35 u |
1 x 7 = 7 u |
Change |
No Change |
- 20 |
After |
7 x 5 = 35 u |
1 x 5 = 5 u |
(a)
The number of green stickers remains unchanged.
Make the number of green stickers and red stickers the same using LCM of 5 and 7.
LCM of 5 and 7 = 35
Number of red stickers that Adam gives away
= 7 u - 5 u
= 2 u
2 u = 20
1 u = 20 ÷ 2 = 10
Number of more green stickers than red stickers at first
= 35 u - 7 u
= 28 u
= 28 x 10
= 280
(b)
Number of less red stickers than green stickers in the end
= 35 u - 5 u
= 30 u
= 30 x 10
= 300
Answer(s): (a) 280; (b) 300