A driver traveled at 40 mph for two hours and 30 mph for one-half hour. What was his average rate of speed?

Question

anonymous · Answer

it would be total distance over total time...

40 mph for two hours means 80 miles traveled in 2 hours

30 mph for 1/2 hour means 15 miles traveled in 1/2 hour

total distance is 95 miles
total time is 5/2 hours

$$speed = \frac{distance}{time} = \frac{95 miles}{\frac{5}{2} hours} = \frac{95 \times 2}{5} = 19 \times 2 = 38 mph$$

anonymous · Answer

muplity?

anonymous · Answer

40 X 2 = 80 miles?

anonymous · Answer

yep

anonymous · Answer

30 miles X 1/2 hour?

anonymous · Answer

yup

anonymous · Answer

$$distance = speed \times time$$

anonymous · Answer

do you have any further questions? i got to go

anonymous · Answer

How did you get 5/2 hours? Please explain to me.

kropot72 · Answer

If you drive for two hours at 40 miles per hour how many miles would you have travelled?

kropot72 · Answer

@Pluto113 Are you there?

anonymous · Answer

Yes, I am here.

anonymous · Answer

40 miles x 2 hours = 80 miles, right?

anonymous · Answer

30 miles x 1/2 hours = 15 miles, right?

I am not sure what the answer, 5/2 hours is...

anonymous · Answer

That means 2 hours + 1/2 hours = 2.5 or 5/2 hours, right? I just want to comperhend myself.

kropot72 · Answer

And if you travel for 1/2 hour at 30 miles per hour you would have travelled 15 miles.
80 miles are travelled in 2 hours and 15 miles are travelled in 1/2 hour.
Total distance = 80 + 15 = 95 miles
Total time taken = 2 + 1/2 = 2 1/2 hours = 5/2 hours
The mixed number 2 1/2 has been converted to a fraction 5/2
Do you understand?