To work out percentage change you takeaway the original number by the new number (New number-Original number) in this case 24-60=(-36), then divide the decreased amount by the original number and multiply the answer by 100 (Decrease amount ÷ Original number x 100) for this question you'd do (-36)÷60=(-0.6) then (-0.6)x100=(-60).
The minus shows its a decrease in percentage by 60%
