Eric had
79 as many pens as Eva. After Eric bought another 16 pens, he had 10 less pens than Eva. How many pens did Eric have at first?
|
Eric |
Eva |
Before |
7 u |
9 u |
Change |
+ 16 |
|
After |
7 u + 16 |
9 u |
Eva had 10 more pens than Eric in the end. So, if Eric had another 10 pens, he would have the same number of pens as Eva.
9 u = 7 u + 16 + 10
9 u - 7 u = 16 + 10
2 u = 26
1 u = 26 ÷ 2 = 13
Number of pens that Eric had at first
= 7 u
= 7 x 13
= 91
Answer: 91