Xandra and Gillian collected stamps. Xandra gave 20% of her stamps to Gillian. As a result, Gillian's stamps increased by 70%. If Xandra had 308 stamps left, find the total number of stamps the two girls had at first.
| |
Xandra |
Gillian |
Comparing the change
in Gillian's stamps |
| Before |
5x7 =
35 u |
|
10x1 =
10 u |
| Change |
- 1x7 =
- 7 u |
+ 1x7 =
+ 7 u |
+ 7x1 =
+ 7 u |
| After |
4x7 =
28 u |
|
17x1 =
17 u |
20% =
20100 =
15 70% =
70100 =
710 The number of stamps that Xandra gave to Gillian is repeated. Make the number of stamps that Xandra gave to Gillian the same. LCM of 1 and 7 is 7.
Number of stamps that Xandra had in the end = 28 u
28 u = 308
1 u = 308 ÷ 28 = 11
Number of stamps that Xandra and Gillian had at first
= 35 u + 10 u
= 45 u
= 45 x 11
= 495
Answer(s): 495
