Vanessa had 90% as many jelly beans as Risa. Vanessa gave away 25% of her jelly beans and Risa bought another 60 jelly beans. As a result, Vanessa now has 60% as many jelly beans as Risa. Find the number of jelly beans that Risa had at first.
| |
Vanessa |
Risa |
| Before |
9x3 |
10x3 |
| Change |
- 2.25x3 |
+ 60 |
| After |
6.75x3 |
10x3 + 60 |
Comparing Vanessa and
Risa in the end |
3x6.75 |
5x6.75 |
| |
Vanessa |
Risa |
| Before |
27 u |
30 u |
| Change |
- 6.75 u |
+ 60 |
After
|
20.25 u
|
30 u + 60 =
33.75 u |
90% =
90100 =
91025% x 9
=
25100 x 9
= 2.25
60% =
60100 =
35The number of jelly beans that Vanessa had in the end is repeated.
Make the number of jelly beans that Vanessa had in the end the same.
The number of jelly beans that Risa had in the end is repeated.
30 u + 60 = 33.75 u
33.75 u - 30 u = 60
3.75 u = 60
1 u = 60 ÷ 3.75 = 16
Number of jelly beans that Risa had at first
= 30 u
= 30 x 16
= 480
Answer: 480
