Tiffany collected 4 times as many marbles as Ethan. After Ethan collected another 90 marbles, both of them had an equal number of marbles. How many marbles did Tiffany collect?
| |
Tiffany |
Ethan |
| Before |
4 u |
1 u |
| Change |
|
+ 90 |
| After |
4 u |
1 u + 90 |
The number of marbles that Tiffany and Ethan collected in the end is equal.
4 u = 1 u + 90
4 u - 1 u = 90
3 u = 90
1 u = 90 ÷ 3 = 30
Number of marbles that Tiffany collected
= 4 u
= 4 x 30
= 120
Answer(s): 120
