Tammy and Anna collected stamps. Tammy gave 40% of her stamps to Anna. As a result, Anna's stamps increased by 70%. If Tammy had 147 stamps left, find the total number of stamps the two girls had at first.
| |
Tammy |
Anna |
Comparing the change
in Anna's stamps |
| 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 stamps that Tammy gave to Anna is repeated. Make the number of stamps that Tammy gave to Anna the same. LCM of 2 and 7 is 14.
Number of stamps that Tammy had in the end = 21 u
21 u = 147
1 u = 147 ÷ 21 = 7
Number of stamps that Tammy and Anna had at first
= 35 u + 20 u
= 55 u
= 55 x 7
= 385
Answer(s): 385
