Gillian had 90% as many lollipops as Emma. Gillian gave away 20% of her lollipops and Emma bought another 20 lollipops. As a result, Gillian now has 70% as many lollipops as Emma. Find the number of lollipops that Emma had at first.
| |
Gillian |
Emma |
| Before |
9x7 |
10x7 |
| Change |
- 1.8x7 |
+ 20 |
| After |
7.2x7 |
10x7 + 20 |
Comparing Gillian and
Emma in the end |
7x7.2 |
10x7.2 |
| |
Gillian |
Emma |
| Before |
63 u |
70 u |
| Change |
- 12.6 u |
+ 20 |
After
|
50.4 u
|
70 u + 20 =
72 u |
90% =
90100 =
91020% x 9
=
20100 x 9
= 1.8
70% =
70100 =
710The number of lollipops that Gillian had in the end is repeated.
Make the number of lollipops that Gillian had in the end the same.
The number of lollipops that Emma had in the end is repeated.
70 u + 20 = 72 u
72 u - 70 u = 20
2 u = 20
1 u = 20 ÷ 2 = 10
Number of lollipops that Emma had at first
= 70 u
= 70 x 10
= 700
Answer: 700
