Charlie had
79 as many erasers as Anna. After Charlie bought another 11 erasers, he had 13 less erasers than Anna. How many erasers did Charlie have at first?
|
Charlie |
Anna |
Before |
7 u |
9 u |
Change |
+ 11 |
|
After |
7 u + 11 |
9 u |
Anna had 13 more erasers than Charlie in the end. So, if Charlie had another 13 erasers, he would have the same number of erasers as Anna.
9 u = 7 u + 11 + 13
9 u - 7 u = 11 + 13
2 u = 24
1 u = 24 ÷ 2 = 12
Number of erasers that Charlie had at first
= 7 u
= 7 x 12
= 84
Answer: 84