A potting mixture contains 12.0% peat moss and 6.00% vermiculite. How much peat moss and how much vermiculite must be added to 100lb of this mixture to produce a new mixture having 15.0% peat and 15.0% vermiculite?

Answer is 3% more peat and 9% more vermiculite.

Step-by-step explanation:

The weight of the initial potting mixture is not given, but the percentage amounts of peat moss & vermiculite are given.

The weight of the new potting mixture is 100lb.

For the new mixture to have 15% peat and 15% vermiculite,

The amount of peat that must be added is 3% of the peat in the initial mixture.

Hint: subtract 12 from 15. Retain the percentage sign.

The amount of vermiculite that must be added is 9% of the vermiculite in the initial mixture.

Hint: subtract 6 from 15. Retain the percentage sign, as that is the scale of measurement here.