Answer:
31 oranges
Explanation:
Let n be the number of oranges and m be the number of bags Mr. Teo has.
If he packs 5 oranges in each bag, then he packs 5m oranges in m bags and since he is short of 4 oranges,
![n=5m-4.](https://img.qammunity.org/2020/formulas/mathematics/high-school/itbfr2gwrequozxrto4nheawyqfnp52sh9.png)
If he packs 4 oranges in each bag, then he packs 4m oranges in m bags and since he has 3 oranges left,
![n=5m+3.](https://img.qammunity.org/2020/formulas/mathematics/high-school/hbws9dm0mt76fi5ph86bvf7uztmvorad0a.png)
Equate right sides of these two equations:
![5m-4=4m+3,\\ \\m=7.](https://img.qammunity.org/2020/formulas/mathematics/high-school/rk3q9iqis6or1r70aqzb3ktu45m19snbmw.png)
Hence,
![n=5\cdot 7-4=31.](https://img.qammunity.org/2020/formulas/mathematics/high-school/z84uoo1csr6y8tg6l60vabjzmwsn9zqsdb.png)