A bicycle tire has a diameter of 70 centimeters. Approximately how man

Question

A bicycle tire has a diameter of 70 centimeters. Approximately how many revolutions does the tire make if the bicycle travels 1 kilometer. (1 kilometer = 1,000 meters = 100,000 centimeters)

A. 150
B. 450
C. 900
D. 1500
E. 2200

Bunuel · Answer

styxnexus · Answer

Diameter = 70 cm, hence radius =35cm. In one revolution the tire will cover the length equivalent to it's perimeter which is equals 2*π*35 cm. So to cover 1km or 100000 cm the cycle will have to move = n*2*π*35 cm
>> n = 100000*7/(2*22*35) = 5000/11 = 450 approx. Hence,  option B. 450

generis · Answer

(circumference)*(# of revolutions) = Distance, so

Number of revolutions =  \frac{Distance}{circumference}

Circumference:   \pi d=70\pi=(70*\frac{22}{7})\approx{220}cm

Distance =   100,000 cm

Number of revolutions: 
  \frac{Distance}{circumference}=\frac{100,000cm}{220cm}\approx{455}   revolutions

Answer B

Mo2men · Answer

Number of revolutions =\frac{Distance}{circumference}

Circumference =  \pi d=70\pi=(70*\frac{22}{7})\approx{220}cm

Distance =   100,000 cm

Number of revolutions =  \frac{Distance}{circumference}=\frac{100,000cm}{220cm}

Here we can make 220 to be 200 to ease the calculation. The answer choices helps to make the approximation.

Number of revolutions =  \frac{Distance}{circumference}=\frac{100,000cm}{200cm}  =  500

The number must be less than 500.

450 is the closest to 500

Answer B

ScottTargetTestPrep · Answer

(note: although we are using the given conversion, 1 kilometer = 1,000 meters)

The circumference of the tire is 70π = 70 x 3.14 = 219.8 cm, which is about 220 cm. Thus, 1 revolution of the tire is about 220cm.

Since 1 km = 1,000 m and 1 m = 100 cm, so 1 km = 1,000 x 100 = 100,000 cm. Thus in 100,000 cm, the number of revolutions is 100,000/220 ≈ 454 ≈ 450 revolutions.

Answer: B

ThatDudeKnows · Answer

Diameter = 70cm
Circumference = 210cm
1km = 1000m = 100000cm
100000/210 = 1000/2 = 500

Answer choice B.

MBAHOUSE · Answer

Rule of three is very practical to the gmat test.

A bicycle tire has a diameter of 70 centimeters. Approximately how man

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A bicycle tire has a diameter of 70 centimeters. Approximately how man

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