Eva maintained an average speed of 35 miles per hour ( mph ) for the first m hours of her road trip. For the next n hours of the trip, she drove at an average speed of 60mph. Eva drove a total of 225 miles in 4.5 hours. Which of the following systems of equations could be used to find how many miles Eva drove in the first m hours of the trip? Choose 1 answer: (A) m+n=225 35 m+60 n=4.5 (B) m+n=4.5 35 m+60 n=225 (C) m+n=225 60 m+35 n=4.5 (D) m+n=4.5 60 m+35 n=225

Question

Eva maintained an average speed of 35 miles per hour (  mph ) for the first  m hours of her road trip. For the next  n hours of the trip, she drove at an average speed of  60mph. Eva drove a total of 225 miles in 4.5 hours. Which of the following systems of equations could be used to find how many miles Eva drove in the first  m hours of the trip? Choose 1 answer: (A)  m+n=225  35 m+60 n=4.5 (B)  m+n=4.5  35 m+60 n=225 (C)  m+n=225  60 m+35 n=4.5 (D)  m+n=4.5  60 m+35 n=225

Bytelearn · Accepted Answer

Understand the problem: Understand the problem. Eva drove for a total of 4.5 hours and covered 225 miles. She drove for m hours at 35 mph and for n hours at 60 mph. We need to find a system of equations that represents this situation.Set up time equation: Set up the first equation based on the total time. Eva drove for m hours and then for n hours, which together should add up to the total time of the trip, which is 4.5 hours. So the first equation should be: m + n = 4.5Set up distance equation: Set up the second equation based on the total distance. Eva drove m hours at 35 mph and n hours at 60 mph. The distance she covered in the first m hours is 35m miles, and the distance she covered in the next n hours is 60n miles. The total distance is 225 miles. So the second equation should be: 35m + 60n = 225Identify correct system: Identify the correct system of equations. Looking at the choices given, we need to find the one that matches the two equations we have set up in Steps 2 and 3. The correct system of equations is: m + n = 4.5 35m + 60n = 225Choose correct answer: Choose the correct answer. The correct answer is the one that matches the system of equations we found in Step 4. This corresponds to choice (B): (B) m + n = 4.5     35m + 60n = 225

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