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