You are an electrician and have taken on a job to repair an

You are an electrician and have taken on a job to repair an electric motor. The motor should spin at 2,500 rotations per minute (rpm); instead, it is spinning at 2,000 rpm. By how much does the rpm need to increase? 12.5% 25% 125% 250% 500%

Solution

Percentage increase is given by: 100*(final value-current value)/current value

                                                        =100*(2500-2000)/2000=25%