*t*minutes after it has been poured is described by the function \(\displaystyle C(t) = 20 + 60(0.95)^t \).

a. How many minutes does it take for the coffee to cool to a temperature of

*d*degrees?

b. About how fast is the temperature dropping when

*t*= 1?

For a. is it just: \(\displaystyle d = 20 + 60(0.95)^t \)??

Could someone help me with both a and b pls?

Thanks.