Question: Find a solution for this math problem: Mark took a test yesterday that consisted of 75 questions. He completed the test at a rate of 5 questions per hour. Today, he took another test of 100 questions at the same rate. If Mark had 8 hours to complete the first test and 6 hours to complete the second one, how many questions did he leave incomplete?
Answer: 
Questions Mark completed in yesterday’s test: 5*8 = 40.
Questions Mark completed in today’s test: 5*6 = 30.
Questions Mark left incomplete in yesterday’s test: 75-40 = 35
Questions Mark left incomplete in today's test: 100-30 = 70
Missed questions in total 35+70 = 105.