Question

If a globe rotates 150 degrees in 5 seconds, how many rotations does it make in 30 seconds? I got 900 seconds for my answer am I right? If not can you tell me the answer with work?

Answer 1

Start with a proportion, to get the number of degrees in 30 seconds:

         (150 degrees / 5 seconds) = ('D' degrees / 30 seconds) .

Cross multiply the proportion:  (150 x 30) = 5 x D

                                                     4,500  =  5 x D

Divide each side by  5 :                  900 = D

The globe turns 900 degrees in 30 seconds.

How many rotations is that ?
Each rotation is 360 degrees.
So 900 degrees is
                               (900 / 360) = 2.5 rotations in 30 seconds.