David had
25 as many stamps as Diana. After David gave away 16 stamps, he had 58 less stamps than Diana. How many stamps did Diana have?
| |
David |
Diana |
| Before |
2 u |
5 u |
| Change |
- 16 |
|
| After |
2 u - 16 |
5 u |
Diana had 58 more stamps than David in the end. So, if David had another 58 stamps, he would have the same number of stamps as Diana.
5 u = 2 u - 16 + 58
5 u - 2 u = 58 - 16
3 u = 42
1 u = 42 ÷ 3 = 14
Number of stamps that Diana had at first
= 5 u
= 5 x 14
= 70
Answer: 70
