Eva and Betty collected erasers. Eva gave 40% of her erasers to Betty. As a result, Betty's erasers increased by 75%. If Eva had 90 erasers left, find the total number of erasers the two girls had at first.
| |
Eva |
Betty |
Comparing the change
in Betty's erasers |
| Before |
5x3 =
15 u |
|
4x2 =
8 u |
| Change |
- 2x3 =
- 6 u |
+ 2x3 =
+ 6 u |
+ 3x2 =
+ 6 u |
| After |
3x3 =
9 u |
|
7x2 =
14 u |
40% =
40100 =
25 75% =
75100 =
34 The number of erasers that Eva gave to Betty is repeated. Make the number of erasers that Eva gave to Betty the same. LCM of 2 and 3 is 6.
Number of erasers that Eva had in the end = 9 u
9 u = 90
1 u = 90 ÷ 9 = 10
Number of erasers that Eva and Betty had at first
= 15 u + 8 u
= 23 u
= 23 x 10
= 230
Answer(s): 230
