Shannon had 81 more erasers than Nora. After Nora gave away
16 of her erasers, Shannon had thrice as many erasers as Nora. How many erasers did Nora have at first?
| |
Shannon |
Nora |
Comparing Shannon and
Nora at first |
81 more |
|
| Before |
15 u |
6 u |
| Change |
|
- 1 u |
| After |
15 u |
5 u |
Comparing Shannon and
Nora in the end |
3x5 =
15 u |
1x5 =
5 u |
Number of erasers that Nora had in the end is repeated. Make the number of erasers that Nora had in the end the same. LCM of 1 and 5 is 5.
Number of erasers that Shannon had at first = 15 u
Number of erasers that Shannon had more than Nora at first
= 15 u - 6 u
= 9 u
9 u = 81
1 u = 81 ÷ 9 = 9
Number of erasers that Nora had at first
= 6 u
= 6 x 9
= 54
Answer(s): 54
