MathDB

Let

r

be the speed in miles per hour at which a wheel,

11

feet in circumference, travels. If the time for a complete rotation of the wheel is shortened by

\tfrac{1}{4}

of a second, the speed

r

is increased by

5

miles per hour. The

r

is:

\text{(A)}\ 9\qquad \text{(B)}\ 10\qquad \text{(C)}\ 10\tfrac{1}{2}\qquad \text{(D)}\ 11\qquad \text{(E)}\ 12

Problem Statement