Jean had 77 more erasers than Sarah. After Sarah gave away
25 of her erasers, Jean had four times as many erasers as Sarah. How many erasers did Sarah have at first?
| |
Jean |
Sarah |
Comparing Jean
and Sarah at first |
77 more |
|
| Before |
12 u |
5 u |
| Change |
|
- 2 u |
| After |
|
3 u |
Comparing Jean
and Sarah in the end |
4x3 =
12 u |
1x3 =
3 u |
The number of erasers that Jean had at first and in the end remains unchanged. Make the number of erasers that Jean had the same. LCM of 12 and 4 is 12.
Number of erasers that Jean had more than Sarah at first
= 12 u - 5 u
= 7 u
7 u = 77
1 u = 77 ÷ 7 = 11
Number of erasers that Sarah had at first
= 5 u
= 5 x 11
= 55
Answer(s): 55
