Seth had
310 as many erasers as Jean. After Seth bought another 7 erasers, he had 14 less erasers than Jean. How many erasers did Seth have at first?
|
Seth |
Jean |
Before |
3 u |
10 u |
Change |
+ 7 |
|
After |
3 u + 7 |
10 u |
Jean had 14 more erasers than Seth in the end. So, if Seth had another 14 erasers, he would have the same number of erasers as Jean.
10 u = 3 u + 7 + 14
10 u - 3 u = 7 + 14
7 u = 21
1 u = 21 ÷ 7 = 3
Number of erasers that Seth had at first
= 3 u
= 3 x 3
= 9
Answer: 9