A propeller revolves 468 times in 52 s. How long will it take the propeller to revolve 756 times?

It would take 84 seconds for the propeller to revolve 756 times.

756 / 468 = 1.6154

1.6154 * 52 seconds = 84 seconds or 1 minute 24 seconds

If the problem asks for the number of revolution in one minute. then.

1 minute = 60 seconds

52 s / 60 s = 0.8666

468 times : 0.8666 = 540 revolutions.

The propeller revolves 9 times per second. so in 84 seconds it will have revolved 756 times.