Betty had $21 more than Diana at first. After Betty and Diana spent an equal amount of money, Diana had
47 as much as Betty. How much money did Betty have left?
| |
Betty |
Diana |
Difference |
| Before |
1 u + $21 |
1 u |
$21 |
| Change |
- 1 |
- 1 |
|
| After |
7 p |
4 p |
3 p |
Difference in the amounts between Betty and Diana
= 7 p - 4 p
= 3 p
Since both Betty and Diana spent an equal amount, the difference in the amounts that Betty and Diana had at first and in the end remains unchanged.
3 p = 21
1 p = 21 ÷ 3 = 7
Amount that Betty had left
= 7 p
= 7 x 7
= $49
Answer(s): $49
