Approximately how many revolutions will be made by a car tire with a 10-inch diameter if the car travels 1⁄2 mile?
Choose the correct choice from the following answers.
A) 120
B) 180
C) 1003
D) 1000
E) 1,440
Diameter of car tire = 10 inches   Radius of car tire = 5 inches = 5*2.54= 
<gadget id="calculator">5*2.54</gadget>
<output>12.7</output>
12.7 cm   Circumference of the car tire= 2*pi * 12.7 = 2 *3.14 *12.7= 79.76 cm   Distance traveled by car = .5 mile = .5 *1.6= 
<gadget id="calculator">.5 *1.6</gadget>
<output>0.8</output>
.8 km= 800 m = 8 * 10^4 cm   Number of revolutions =Distance traveled / Circumference of tire = 8 * 10^4 / 79.76 = 1003   Since the answer choices are far apart we should use estimation in this question .   Ideally ,in the GMAT the conversion between units would be provided .   Answer 1003
<result>C</result>
Approximately how many revolutions will be made by a car tire with a 10-inch diameter if the car travels 1⁄2 mile?