Simon had
25 as many marbles as Dana. After Simon gave away 71 marbles, he had 92 less marbles than Dana. How many marbles did Dana have?
| |
Simon |
Dana |
| Before |
2 u |
5 u |
| Change |
- 71 |
|
| After |
2 u - 71 |
5 u |
Dana had 92 more marbles than Simon in the end. So, if Simon had another 92 marbles, he would have the same number of marbles as Dana.
5 u = 2 u - 71 + 92
5 u - 2 u = 92 - 71
3 u = 21
1 u = 21 ÷ 3 = 7
Number of marbles that Dana had at first
= 5 u
= 5 x 7
= 35
Answer: 35
