**..try this**

A pulley that has a diameter of 8 inches is belted to a pulley that has a diameter of 12 inches. The 8-inch-diameter pulley is running at 1,548 revolutions per minute. If the speeds of the pulleys vary inverselyto their diameters, how many revolutions per minute does the larger pulley make?

---according to question-----

speed=k/diameter......(k=arbitary constant)

now applying for first and second pulley

u get

8=k/1548......(1)

12=k/?..........(2)

get k from ( 1) put it in (2) u get the ans