Zoe and Ivory collected erasers. Zoe gave 20% of her erasers to Ivory. As a result, Ivory's erasers increased by 75%. If Zoe had 144 erasers left, find the total number of erasers the two girls had at first.
| |
Zoe |
Ivory |
Comparing the change
in Ivory's erasers |
| Before |
5x3 =
15 u |
|
4x1 =
4 u |
| Change |
- 1x3 =
- 3 u |
+ 1x3 =
+ 3 u |
+ 3x1 =
+ 3 u |
| After |
4x3 =
12 u |
|
7x1 =
7 u |
20% =
20100 =
15 75% =
75100 =
34 The number of erasers that Zoe gave to Ivory is repeated. Make the number of erasers that Zoe gave to Ivory the same. LCM of 1 and 3 is 3.
Number of erasers that Zoe had in the end = 12 u
12 u = 144
1 u = 144 ÷ 12 = 12
Number of erasers that Zoe and Ivory had at first
= 15 u + 4 u
= 19 u
= 19 x 12
= 228
Answer(s): 228
