Jodi's family produces 48 kg of garbage each week. What is the percentage decrease if they reduce the amount of garbage to 40 kg per week?

In this case, the unknown value is the percentage decrease. The formula to be used for calculating decrease in percentage is:

pd = ((ov-dv) / ov) * 100

where pd=percentage decrease, ov=original value and dv=decremented value. Substituting with the real values the calculation is:

((48-40) / 48) * 100=16.67%

So the percentage decrease in garbage production per week is 16.67%.