The price of apples went from $0.30 per lb to $0.90 per lb in three years. find the rate of change of the price of apples.

Hence, the rate of change of the price of apples is:

                             $ 0.20 per year.

Let P denote the price of apples.

It is given that the initial price of apples is: $ 0.30 per lb.

i.e. P(0)=$ 0.30 per lb.

Also, the price of the apples after three years is:  $ 0.90 per lb.

i.e.  P(3)=$ 0.90 per lb.

Hence, the rate of the change of the price of apples is calculated by:

Now on putting the value in the formula we obtain:

                          The rate of change is:

                             $ 0.20 per year.