Question 72173
The accuracy of a car's speedometer varies directly with the actual speed of the car. A car's speedometer reads 24 miles per hour when the car is actually traveling at 32 miles per hour. When the speedometer reads 51 miles over hour, how fast is the car actually going?
:
Use our old friend the ratio:
{{{24/32}}} = {{{51/s}}}
:
Cross multiply:
24s = 32 * 51
24s = 1632
s = 1632/24
s = 68 mph