The voltage across the primary winding is 350,000 V, and the voltage across the secondary winding is 17,500 V. If the secondary winding has 600 coils, how many coils are in the primary winding?

30

583

12000

332500

The answer is 30 coils. Substitute the variables V2/V1 = T2/T1 where V = voltage, T = coils, 2 = secondary winding, and 1 = primary winding. Let x be the missing variable, you'll get the equation 17500/350000 = 600/x. Divide first the 17500/350000 to get 0.05 then multiply it to 600 to get the answer 30 coils.