There are 4 gear wheels on fixed axles next to each other, as shown. The first one has 30 gears, the second one 15, the third one 60 and the last one 10. How many revolutions does the last gearwheel make when the first one turns through one revolution?

The last gearwheel would make 3 revolutions.

Step-by-step explanation:

The measure of the revolution of a gear per minute is referred to as the speed ratio. The speed ratio is the ratio of the speed of the driver gear to that of the driven gear, or ratio of the number of teeth of the driven gear to the number of teeth of the driver gear.

In the given question, the second and third gears are idlers. while the first is the driver and the fourth the driven.

The revolution of the last gearwheel can be determined by;

Speed ratio =  

                    =

                    =

Speed ratio = 1 : 3

The last gear would make 3 revolutions.

the answer is 31.27mph