Henry Ernest Dudeney/Puzzles and Curious Problems/354 - The Wheels of the Car

Puzzles and Curious Problems by Henry Ernest Dudeney: $354$

The Wheels of the Car

"You see, sir," said the motor-car salesman, "at present the fore-wheel of the car I am selling you makes four revolutions more than the hind-wheel in going $120$ yards;

but if you have the circumference of each wheel reduced by $3$ feet, it would make as many as six revolutions more than the hind-wheel in the same distance."

Why the buyer wished that the difference in the number of revolutions between the two wheels should not be increased does not concern us.

The puzzle is to discover the circumference of each wheel in the first case.

It is quite easy.

Sources

• 1932: Henry Ernest Dudeney: Puzzles and Curious Problems ... (previous) ... (next): Unclassified Problems: $354$. -- The Wheels of the Car
• 1968: Henry Ernest Dudeney: 536 Puzzles & Curious Problems ... (previous) ... (next): Geometrical Problems: Circle Puzzles: $292$. The Wheels of the Car