Problem:
Visvam walks half a mile to get to school each day. His route consists of city blocks of equal length and he takes one minute to walk each block. Today, after walking blocks, Visvam discovers that he has to make a detour, walking blocks of equal length instead of block to reach the next corner. From the time he starts his detour, at what speed, in miles per hour, must Visvam walk in order to arrive at school at his usual time?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
If half a mile is the same as blocks, then one block is miles. Starting from the detour, Visvam has to walk miles. Normally, from this spot Visvam would take minutes to walk to school. Now he has to travel miles in minutes. Note that minutes is hours. This means his speed must be mph.
Thus, is the correct answer.
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions