Eva had 90% as many jelly beans as Gillian. Eva gave away 20% of her jelly beans and Gillian bought another 20 jelly beans. As a result, Eva now has 70% as many jelly beans as Gillian. Find the number of jelly beans that Gillian had at first.
| |
Eva |
Gillian |
| Before |
9x7 |
10x7 |
| Change |
- 1.8x7 |
+ 20 |
| After |
7.2x7 |
10x7 + 20 |
Comparing Eva and
Gillian in the end |
7x7.2 |
10x7.2 |
| |
Eva |
Gillian |
| 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 jelly beans that Eva had in the end is repeated.
Make the number of jelly beans that Eva had in the end the same.
The number of jelly beans that Gillian 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 jelly beans that Gillian had at first
= 70 u
= 70 x 10
= 700
Answer: 700
