The tour bus has traveled the Virst half of your trip at only 40 mph. How fast would your tour bus have to travel to have an average speed of 70 mph?

Question

it's late and I'm not understanding anything anymore. Can someone please help?

Answer 1

Since the speed for first half is known, we have to find the speed for the second half.  The average is 70 mph.  Average means to add all the values and divide the result by the number of values.

 

Let x = the speed for the second half of the trip

 

 

(40 + x) / 2 = 70

 

 

Multiply both sides of the equation by 2.

 

40 + x = 140

 

 

Subtract 40 on both sides of the equation.

 

x = 100

 

 

The bus will need to travel 100 mph during the second half.