Penelope and Sabrina collected erasers. Penelope gave 20% of her erasers to Sabrina. As a result, Sabrina's erasers increased by 70%. If Penelope had 224 erasers left, find the total number of erasers the two girls had at first.
| |
Penelope |
Sabrina |
Comparing the change
in Sabrina's erasers |
| Before |
5x7 =
35 u |
|
10x1 =
10 u |
| Change |
- 1x7 =
- 7 u |
+ 1x7 =
+ 7 u |
+ 7x1 =
+ 7 u |
| After |
4x7 =
28 u |
|
17x1 =
17 u |
20% =
20100 =
15 70% =
70100 =
710 The number of erasers that Penelope gave to Sabrina is repeated. Make the number of erasers that Penelope gave to Sabrina the same. LCM of 1 and 7 is 7.
Number of erasers that Penelope had in the end = 28 u
28 u = 224
1 u = 224 ÷ 28 = 8
Number of erasers that Penelope and Sabrina had at first
= 35 u + 10 u
= 45 u
= 45 x 8
= 360
Answer(s): 360
