Nora and Jen collected erasers. Nora gave 10% of her erasers to Jen. As a result, Jen's erasers increased by 70%. If Nora had 126 erasers left, find the total number of erasers the two girls had at first.
| |
Nora |
Jen |
Comparing the change
in Jen's erasers |
| Before |
10x7 =
70 u |
|
10x1 =
10 u |
| Change |
- 1x7 =
- 7 u |
+ 1x7 =
+ 7 u |
+ 7x1 =
+ 7 u |
| After |
9x7 =
63 u |
|
17x1 =
17 u |
10% =
10100 =
110 70% =
70100 =
710 The number of erasers that Nora gave to Jen is repeated. Make the number of erasers that Nora gave to Jen the same. LCM of 1 and 7 is 7.
Number of erasers that Nora had in the end = 63 u
63 u = 126
1 u = 126 ÷ 63 = 2
Number of erasers that Nora and Jen had at first
= 70 u + 10 u
= 80 u
= 80 x 2
= 160
Answer(s): 160
