A car went 346 miles in 6 hours, traveling part of the time at 55 miles per hour and part of the time at 65 miles per hour. How long did the car travel at each speed?

The car traveled;

a) for 4.4 hours with speed of 55 miles / hour

and

b) for 1.6 hours with speed of 65 miles / hour

Explanation:

Let the time taken by the car while moving with speed 55 miles per hour = x hours

Then remaining time the car move at speed of 65 miles per hour is = 6-x hours

using formula

S = V * T

Where S = distance

V = speed

T = time

First case

S=?

V=55 m/h

T = x hours

put values in formula above

==> S = V * T

==> S1 = 55 * x = 55 x miles

Second case

S=?

V = 65 m/h

T = (6-x) hours

Putting values in formula above

S = V * T

==> S2 = 65 * (6-x) = 65 (6-x) miles

Total distance covered by the car = S1+S2=55x+65 (6-x)

= 55x + 390-65x

= - 10x+390 miles

But total distance given is 346 miles

==> - 10x+390=346

==> - 10x=346-390

==> - 10x = - 44

==> x=44/10=4.4 hours

So, car traveled for 4.4 hours with speed of 55 miles / hour and for 1.6 hours with speed of 65 miles / hour