Sarah had 43 more smoothed stones than Gwen at first. After Sarah bought another 17 smoothed stones, she had thrice as many smoothed stones as Gwen. How many smoothed stones did Sarah have at first?
| |
Sarah |
Gwen |
| Before |
1 u + 43 |
1 u |
| Change |
+ 17 |
|
| After |
1 u + 60 |
1 u |
Number of smoothed stones Sarah had in the end
= 3 x 1 u
= 3 u
3 u = 1 u + 60
3 u - 1 u = 60
2 u = 60
1 u = 60 ÷ 2 = 30
Number of smoothed stones Sarah had at first
= 1 u + 43
= 30 + 43
= 73
Answer(s): 73
