Three girls, Gillian, Irene and Kylie had a total of 3120 stamps. Some exchanges were made. First, Gillian gave Irene as many stamps as Irene had. After that, Irene gave
15 of whatever she had then to Kylie. Finally, Kylie gave
13 of whatever she had to Gillian. As a result, they each had the same number of stamps. How many stamps did Gillian have at first?
|
Gillian |
Irene |
Kylie |
Total |
Before 1 |
? |
1 u |
|
3120 |
Change 1 |
- 1 u |
+ 1 u |
|
|
After 1 |
|
2 u |
|
|
Before 2 |
|
5 p |
|
3120 |
Change 2 |
|
- 1 p |
+ 1 p |
|
After 2 |
|
4 p |
|
|
Before 3 |
|
|
3 boxes |
3120 |
Change 3 |
+ 1 box |
|
- 1 box |
|
After 3 |
|
|
2 boxes |
|
After 3 |
1 group |
1 group |
1 group |
3120 |
3 groups = 3120
1 group = 3120 ÷ 3 = 1040
1 group = 2 boxes 2 boxes = 1040
1 box = 1040 ÷ 2 = 520
4 p = 1 group
1 p = 1040 ÷ 4 = 260
5 p = 5 x 260 = 1300
5 p = 2 u
2 u = 1300
1 u = 1300 ÷ 2 = 650
Number of stamps that Gillian had at first
= 1 group - 1 box + 1 u
= 1040 - 520 + 650
= 1170
Answer(s): 1170