Adam has 4 times as many red stickers as green stickers.
After he gives away 21 green stickers,
Adam has 7 times as many red stickers 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 x 7 = 28 u |
1 x 7 = 7 u |
Change |
No Change |
- 21 |
After |
7 x 4 = 28 u |
1 x 4 = 4 u |
(a)
The number of red stickers remains unchanged.
Make the number of red stickers and green stickers the same using LCM of 4 and 7.
LCM of 4 and 7 = 28
Number of green stickers that Adam gives away
= 7 u - 4 u
= 3 u
3 u = 21
1 u = 21 ÷ 3 = 7
Number of more red stickers than green stickers at first
= 28 u - 7 u
= 21 u
= 21 x 7
= 147
(b)
Number of less green stickers than red stickers in the end
= 28 u - 4 u
= 24 u
= 24 x 7
= 168
Answer(s): (a) 147; (b) 168