Sean had
25 as many buttons as Olivia. After Sean bought another 17 buttons, he had 13 less buttons than Olivia. How many buttons did Sean have at first?
|
Sean |
Olivia |
Before |
2 u |
5 u |
Change |
+ 17 |
|
After |
2 u + 17 |
5 u |
Olivia had 13 more buttons than Sean in the end. So, if Sean had another 13 buttons, he would have the same number of buttons as Olivia.
5 u = 2 u + 17 + 13
5 u - 2 u = 17 + 13
3 u = 30
1 u = 30 ÷ 3 = 10
Number of buttons that Sean had at first
= 2 u
= 2 x 10
= 20
Answer: 20