What are the solutions to the following math problems?

The correct option is D.
The answer is $\boxed{\text{D. 96}}$

2)

The correct option is D.
The answer is $\boxed{\text{D. 6}}$

3)

The correct option is A.
The answer is $\boxed{\text{A. 468}}$

4)

The correct option is D.
The answer is $\boxed{\text{D. 35}}$

5)

The correct option is D.
The answer is $\boxed{\text{D. 31.5}}$

6)

The correct option is B.
The answer is $\boxed{\text{B. 30.3}}$

7)

The options provided are A. 649. There might be a slight discrepancy or rounding in the options, but based on the exact calculation, 650 is the result. Since 649 is the closest option, it might be a typo in the question or options. Assuming the question expects the exact calculation, the result is 650. If forced to choose from the given options, none are exactly 650. However, if there was a typo and 649 was intended to be 650, then A would be the answer. Without further clarification, I will provide the calculated answer.
The answer is $\boxed{650}$