For a new car, the gas mileage in terms of its speed x is modeled by the function `G(x)=-1/28x^2+3x-31` , where `15 le x le 90`, and x is speed in miles per hour and G is miles per gallon. At what speed, in miles per hour, does the car attain its best gas mileage ?

Find the range of the function (ii) G(x)=3-2x^2, where -4 le x le 5.

Find the range of the function (ii) g(x)=2-3x, where -3 le x le2 .

The braking distance, y feet, for Damon's car to come to a complete stop is modeled by y = (3(x^(2) + 10x))/(40) , where x is the speed of the car in miles per hour. According to this model, which of the following is the maximum speed, in miles per hour, Damon can be driving so that the braking distance is less than or equal to 150 feet?

If a car moves at rate of 54 Km per hour , what is its speed in metres per second ?

A man drove a car at an average rate of speed of 45 miles per hour for the first 3 hours of a 7-hour car trip. If the average rate speed for the entire trip was 53 miles per hour, what was the average rate of speed in miles per hour for the remaining part of the trip?

The speed, in miles per hour, of a particular experimental spacecraft t minutes after it is lauched is modeled by the function M, which is defined as M(t)=200(3)^((t)/(3)) . According to this model, what is the speed, in miles per hour, 9 minutes after the spacecraft is lauched?

An elephant traveled 7 miles at an average rate of 4 miles per hour and then traveled the next 7 miles at an average rate of 1 mile per hour. What was the average speed, in miles per hour, of the elephant for the 14 miles?

Brian plans to complete a 100-mile bike race for charity. According to his registration materials, he will need to ride at an average speed of 12.5 miles per hour if he wants to complete the course before it closes. On a pratice ride the week before the race, Brain rides 60 miles and trackes his speed. For the first 30 miles, his average speed is 16 miles per hour, and for the next 30 miles, his average speed is 15 miles per hour. If Brian can match these speeds for the first 60 miles of the charity race, then he rests for that total of 1 hour after that, what approximately speed must he maintain for the last 40 miles in order to complete the ride on time?