Circles, SM-Bank 037 MC

A car tyre has a circumference of 120 cm.

Which of these is closest to the radius of the tyre?

\(9.5\ \text{cm}\)
\(19.1\ \text{cm}\)
\(38.0\ \text{cm}\)
\(753.6\ \text{cm}\)

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\(B\)

Show Worked Solution

\(C\)	\(=2 \pi r\)
\(120\)	\(=2\times \pi\times r\)
\(r\)	\(=\dfrac{120}{2 \pi}\)
	\(=19.098\dots\)
	\(\approx 19.1\ \text{cm}\)

\(\Rightarrow B\)