Final answer:
To calculate the remaining time, we need to find out how much time Yan has already spent on the 5 math problems he finished. Then, subtract the time spent from the total time allotted for all the problems to find the remaining time. The correct answer is D) 43 minutes.
Step-by-step explanation:
To calculate the remaining time, we need to find out how much time Yan has already spent on the 5 math problems he finished. Since each problem takes 15 minutes to complete, the total time spent is 5 x 15 = 75 minutes so far. Now, we can find the remaining time by subtracting the time spent from the total time allotted for all the problems: 45 x 15 - 75 = 675 - 75 = 600 minutes. However, the question asks for the answer to the nearest minute, so we need to round the result. Since 600 minutes is equal to 10 hours, the remaining time is approximately 10 hours, which is equivalent to 600 minutes. Therefore, the answer is 600 minutes. The correct option is D) 43 minutes.