Xuan bought four times as many muffins as Oscar. After Xuan ate 7 muffins, she had 11 more muffins than Oscar. How many muffins did they buy altogether?
| |
Xuan |
Oscar |
Total |
| Before |
4 u |
1 u |
5 u |
| Change |
- 7 |
|
|
| After |
4 u - 7 |
1 u |
|
The number of muffins that Oscar had remains unchanged.
If Oscar had another 11 muffins in the end, the number of muffins that Xuan and Oscar had would be the same.
4 u - 7 = 1 u + 11
4 u - 1 u = 11 + 7
3 u = 18
1 u = 18 ÷ 3 = 6
Total number of muffins
= 4 u + 1 u
= 5 u
= 5 x 6
= 30
Answer(s): 30
