Lucy and Min collected marbles. Min gave 70% of her marbles to Lucy. As a result, Lucy's marbles increased by 25%. If Lucy had 105 marbles left, find the total number of marbles the two girls had at first.
| |
Comparing the change
in Min's marbles |
Min |
Lucy |
| Before |
10x1 =
10 u |
|
4x7 =
28 u |
| Change |
- 7x1 =
- 7 u |
- 1x7 =
- 7 u |
+ 1x7 =
+ 7 u |
| After |
3x1 =
3 u |
|
5x7 =
35 u |
70% =
70100 =
710 25% =
25100 =
14 The number of marbles that Lucy gave to Min is repeated. Make the number of marbles that Lucy gave to Min the same. LCM of 1 and 7 is 7.
Number of marbles that Lucy had in the end = 35 u
35 u = 105
1 u = 105 ÷ 35 = 3
Number of marbles that Min and Lucy had at first
= 10 u + 28 u
= 38 u
= 38 x 3
= 114
Answer(s): 114
