contestada


The time t is required a certain distance varies inversely with the speed r if it takes 4 hours to drive the distance at 40 miles per hour how long will it take to drive the same distance at 55 miles per hour.
A. about 2.91 hours
B.160 hours
C. about 22 hours
D. about 5.50 hours
Is the answer A?

Respuesta :

CastleRook
This is the concept of rates we are required to get the time taken two drive between two points stated;
here we use the formula;
speed=distance/time
therefore;
distance=speed*time
the distance covered by the driver given that he drove for 4 hours at a speed of 40 mph;
thus;
distance=40*4=160 miles
thus the time taken if he traveled at a speed of 55 mph will be:
time=distance/speed
time=160/55
time=2.9090≈2.91 hours

The correct answer is A