An air freshener starts with 25 grams and evaporates. in each of the following cases, write a formula for the quantity, q grams, of air freshener remaining t days after the start.
(a) the decrease is 4 grams per day.
(b) the decrease is 9% per day.
(c) the decrease is at a continuous rate of 12% per day.

A) Decrease is a constant rate. Therefore the function will be linear.

Q = 25 - 4t

b) Decrease is exponential. You will have a exponential function.

Q = 25(1-.09)^t  = 25(.91)^t

c) Decrease is exponential. You will have a continuous exponential function.

Q = 25e^(-.12t)

B. 0.067

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

Number of arrangements:

The number of possible arrangements of n elements is given by:

Desired outcomes

First red(10 - (5+2) = 3 possible)

Last red(2 possible).

Middle 8 arranged in any way.

So

Total outcomes:

Arrangements of 10 elements. So

What is the probability that the first and last blouse are both red?

The correct answer is given by option B.