# Math

While driving on the highway, Dave averages 60 miles per hour. In the city, he averages 30 miles per hour. On a trip to his grandmother's house, Dave drives 2 3/5 hours on the highway and 1 1/5 hours in the city.

1. 👍 0
2. 👎 0
3. 👁 172
1. The question: What is Dave's average speed for the entire trip to his grandmother's house? Round to the nearest tenth.

1. 👍 0
2. 👎 0
2. average speed = totaldistance/totaltime
since for each leg of the trip, distance = speed * time, we have

avgspeed = ((2 3/5 * 60)+(1 1/5 * 30))/(2 3/5 + 1 1/5)
= (156+36)/(3 4/5) = ?

1. 👍 0
2. 👎 0
3. So I got 50.52631..... and I rounded that to 50.5. Is this correct?

1. 👍 0
2. 👎 0

## Similar Questions

1. ### math

the ratio of the distances a 7-iron and a 5- iron will dirve a golf ball is 5 to 6. if a golfer averages 153 yards with a 7- iron, how far should he averages with a 5-iron?

asked by Anonymous on September 26, 2010
2. ### Statistics

Suppose that grade point averages of undergraduate students at one university have a bell-shaped distribution with a mean of 2.62 and a standard deviation of 0.43. Using the empirical rule, what percentage of the students have

asked by Jose on September 18, 2017
3. ### algebra

car averages 20 miles per gallon of gas in city driving and 30 miles per gallon in highway driving. At these rates, how many gallons of gas will the car use on a 300-mile trip if 4/5 of the trip is highway driving and the rest is

asked by Mar on August 4, 2016
4. ### algebra

It takes a passenger train 2 hours less time than it takes a freight train to make the trip from Central City to Clear Creek. The passenger train averages 96mi/hr while the freight train averages 64mi/hr. How far is it from

asked by Samantha on November 11, 2012
5. ### Algebra 1

Two jets leave Marble Airport at 3 pm, one traveling east and the other traveling west. The westbound jet averages 625km/h and the eastbound jet averages 825 km/h. At what time will the jets be 725 km apart?

asked by Suzie on April 10, 2018
1. ### math

if a car averages 11 1/8 miles to a gallon of gas, how many miles can it travel on 18 gallons of gas?

asked by Anonymous on January 22, 2014
2. ### math

two airplanes left the same airport traveling in opposite direction. if one airplane averages 400 miles per hour and the other airplane averages 250 miles per hour, in how many hours will the distance between the two planes be

asked by anonymous on April 28, 2007
3. ### Algebra

Two trains start from the same place at the same time. They travel i~ opposite directions. One averages 60 miles per hour and the other averages 80 miles per hour. After how long will they be 420 miles apart?

asked by LIbby on April 2, 2012
4. ### algebra

A relay team is going to participate in a 150-mile bicycle race. One rider averages 12 miles per hour. The second averages 16 miles per hour. Write a function modeling their trip, where x = the hours ridden by the first bicyclist

asked by garry on May 14, 2015
5. ### algebra

Sean and Barry are practicing in a 30-mile bike race. Sean averages 20 miles per hour and Barry averages 15 miles per hour. Howm many miles will Barry be from the finish line when Sean finishes the race?

asked by Astrid on April 22, 2008