Tom went on a 3 Day road trip in which he drove the same number of miles each day. He drove 42 mph the first day. He drove 48 mph the second day. On the last day he drove a x mph. His average speed for the whole trip was 47 mph. Find x and write your answer to the nearest hundredth.
I added (42+48+x) divided by three equals 47 and got x = 51 mph
Looks good to me.
I tend to avoid fractions where possible, so I'd probably have done it as
42+48+x = 3*47
Perry goes for a 4-hour trip through towns and on country roads. If she averages 65 mph on country roads and 25 mph through towns, and she travels three times as far on country roads as she does through towns, what is the total length of her trips?
To solve this problem, we can set up an equation using the average speed formula:
Average Speed = Total Distance / Total Time
We know that Tom's average speed for the whole trip was 47 mph. Since the distance he traveled each day was the same, we can assume the total distance is three times the distance he traveled on one day.
Let's calculate the total distance using the formula:
Average Speed = Total Distance / Total Time
47 = 3 * (distance per day) / (3 days)
Simplifying the equation:
47 = distance per day / 1
Now, we need to find the distance per day. We know that Tom drove 42 mph the first day, 48 mph the second day, and his speed on the last day was x mph. So, the distance for each day would be:
Distance 1 = 42 miles
Distance 2 = 48 miles
Distance 3 = x miles
Now, let's substitute the values into our equation:
47 = (42 + 48 + x) / 3
Now, we can solve for x by multiplying both sides of the equation by 3:
3 * 47 = 42 + 48 + x
141 = 90 + x
Subtracting 90 from both sides of the equation:
51 = x
Therefore, the value of x (the speed on the last day) is 51 mph.