Answer:
The contestant's final score is 20.
Explanation:
Let's form this word problem into a written problem.
![30 + 15 - 25](https://img.qammunity.org/2019/formulas/mathematics/middle-school/dssj38qyh6df1t7anprfo74jvxoqb5cswe.png)
Then, using addition and subtraction, we can determine how many points the contestant is left with. Firstly, add 30 and 15 together.
![30 + 15 = 45](https://img.qammunity.org/2019/formulas/mathematics/middle-school/41db3qqc8hmjv7l23jqqv6q1rhjv7ygyeq.png)
Then, subtract 25 from 45.
![45 - 25 = 20](https://img.qammunity.org/2019/formulas/mathematics/middle-school/mmyvzp79ppzxsrlche26gqjr2e0z4mp2vy.png)
Thus, the contestant is left with 20 points.