Cathy and Jane collected marbles. Jane gave 70% of her marbles to Cathy. As a result, Cathy's marbles increased by 30%. If Cathy had 182 marbles left, find the total number of marbles the two girls had at first.
| |
Comparing the change
in Jane's marbles |
Jane |
Cathy |
| Before |
10x3 =
30 u |
|
10x7 =
70 u |
| Change |
- 7x3 =
- 21 u |
- 3x7 =
- 21 u |
+ 3x7 =
+ 21 u |
| After |
3x3 =
9 u |
|
13x7 =
91 u |
70% =
70100 =
710 30% =
30100 =
310 The number of marbles that Cathy gave to Jane is repeated. Make the number of marbles that Cathy gave to Jane the same. LCM of 3 and 7 is 21.
Number of marbles that Cathy had in the end = 91 u
91 u = 182
1 u = 182 ÷ 91 = 2
Number of marbles that Jane and Cathy had at first
= 30 u + 70 u
= 100 u
= 100 x 2
= 200
Answer(s): 200
