Give the step-by-step reasoning process and then the final answer. Sam earns $10 an hour on Math tutoring. For the first month, he earned $200; and for the second month, he earned $150 more than the first month. How many hours did he spend on tutoring for two months?
For the second month, Sam earned $200 + $150 = $350. So, he earned a total of $200 + $350 = $550 for the first two months. Therefore, he spent $550 / $10 = 55 hours on math tutoring for the first two months.
The final answer: 55.