Jen and Eva collected erasers. Jen gave 10% of her erasers to Eva. As a result, Eva's erasers increased by 75%. If Jen had 324 erasers left, find the total number of erasers the two girls had at first.
| |
Jen |
Eva |
Comparing the change
in Eva's erasers |
| Before |
10x3 =
30 u |
|
4x1 =
4 u |
| Change |
- 1x3 =
- 3 u |
+ 1x3 =
+ 3 u |
+ 3x1 =
+ 3 u |
| After |
9x3 =
27 u |
|
7x1 =
7 u |
10% =
10100 =
110 75% =
75100 =
34 The number of erasers that Jen gave to Eva is repeated. Make the number of erasers that Jen gave to Eva the same. LCM of 1 and 3 is 3.
Number of erasers that Jen had in the end = 27 u
27 u = 324
1 u = 324 ÷ 27 = 12
Number of erasers that Jen and Eva had at first
= 30 u + 4 u
= 34 u
= 34 x 12
= 408
Answer(s): 408
