Question

multiply/divide rational numbers
a tire on a miniature car has a diameter of 1.468 inches. the circumference of a tire for a full size car is 65.97 inches.
to the nearest tenth, what is the circumference of the miniature tire? (c = πd)
a 3.9 inches
b 4.6 inches
c 5.1 inches
d 6.3 inches
to the nearest tenth, how many times greater is the circumference of the full size cars tire when compared to the circumference of the miniature cars tire?
a 8.5 times greater
b 12.2 times greater
c 14.3 times greater
d 15.2 times greater

Explanation:

Step1: Calculate the circumference of the miniature tire

Given the formula \(C=\pi d\), where \(d = 1.468\) inches and \(\pi\approx3.14\).
\(C=\pi\times1.468\approx3.14\times1.468 = 4.61952\) inches. Rounding to the nearest tenth, \(C\approx4.6\) inches.

Step2: Calculate how many times greater the full - size tire's circumference is

The circumference of the full - size tire \(C_{full}=65.97\) inches, and the circumference of the miniature tire \(C_{mini}\approx4.6\) inches.
The ratio \(n=\frac{C_{full}}{C_{mini}}=\frac{65.97}{4.6}\approx14.3\)

Answer:

For the first question: B. 4.6 inches
For the second question: C. 14.3 times greater