Known facts:
A line shaft rotating at 250 rpm, a grinder shaft that turns at 1200 rpm diameter of grinder pulley is 5 inches.
1. Proportion equation
350/1200 = 5/x
2. Cross multiply
1200*5=250*x
x=(1200*5)/250 = (24*50*5)/(5*50) = 24
The big wheel diameter is 24 inches
