Gillian and Mary collected marbles. Gillian gave 40% of her marbles to Mary. As a result, Mary's marbles increased by 70%. If Gillian had 105 marbles left, find the total number of marbles the two girls had at first.
| |
Gillian |
Mary |
Comparing the change
in Mary's marbles |
| Before |
5x7 =
35 u |
|
10x2 =
20 u |
| Change |
- 2x7 =
- 14 u |
+ 2x7 =
+ 14 u |
+ 7x2 =
+ 14 u |
| After |
3x7 =
21 u |
|
17x2 =
34 u |
40% =
40100 =
25 70% =
70100 =
710 The number of marbles that Gillian gave to Mary is repeated. Make the number of marbles that Gillian gave to Mary the same. LCM of 2 and 7 is 14.
Number of marbles that Gillian had in the end = 21 u
21 u = 105
1 u = 105 ÷ 21 = 5
Number of marbles that Gillian and Mary had at first
= 35 u + 20 u
= 55 u
= 55 x 5
= 275
Answer(s): 275
