Xuan and Jaslyn collected coins. Jaslyn gave 70% of her coins to Xuan. As a result, Xuan's coins increased by 40%. If Xuan had 490 coins left, find the total number of coins the two girls had at first.
| |
Comparing the change
in Jaslyn's coins |
Jaslyn |
Xuan |
| Before |
10x2 =
20 u |
|
5x7 =
35 u |
| Change |
- 7x2 =
- 14 u |
- 2x7 =
- 14 u |
+ 2x7 =
+ 14 u |
| After |
3x2 =
6 u |
|
7x7 =
49 u |
70% =
70100 =
710 40% =
40100 =
25 The number of coins that Xuan gave to Jaslyn is repeated. Make the number of coins that Xuan gave to Jaslyn the same. LCM of 2 and 7 is 14.
Number of coins that Xuan had in the end = 49 u
49 u = 490
1 u = 490 ÷ 49 = 10
Number of coins that Jaslyn and Xuan had at first
= 20 u + 35 u
= 55 u
= 55 x 10
= 550
Answer(s): 550
