Question

A circular wheel $28$ inches in diameter rotates the same number of inches per second as a circular wheel$35$ inches diameter. If the smaller wheel makes x revolutions per second, how many revolutions per minute does the larger wheel make in terms of $x$.

• A. $12x$
• B. $48x$
• C. $34x$
• D. $36x$

Answer 1

Answer: (B)

$48x$

We know that, 1 revolution of the circle = Circumference of the circle

1 revolution of a circle with the diameter of 28 inches = $=\pi d=28\pi$ inches

Therefore, x revolutions per second $=28\pi x$ inches per second

= $60\times 28\pi x$ inches per minute

According to the given condition,

$60\times 28\pi x=35\pi n$

$⟹n=\frac{60\times 28x}{35}=48x$

Hence, (B) is the correct answer.