Question

The swimming pool is open when the high temperature is higher than 2 0 ∘ C 20 ∘ C. Lainey tried to swim on Monday and Thursday (which was 3 3 days later). The pool was open on Monday, but it was closed on Thursday. The high temperature was 3 0 ∘ C 30 ∘ C on Monday, but decreased at a constant rate in the next 3 3 days. Write an inequality to determine the rate of temperature decrease in degrees Celsius per day, d d, from Monday to Thursday.

Answer 1

Answer:

$30-3d\leq20$  

Step-by-step explanation:  

Let d represent the rate of temperature decrease in degrees Celsius per day from Monday to Thursday.  

As temperature decreased at a constant rate in the next 3 days, so the rate of temperature will decrease 3d degree Celsius in 3 days.

We are told that the pool was open on Monday. The high temperature was $30^oC$ on Monday. So the decrease in temperature from Monday to Thursday will be $30-3d$.

We have been given that the swimming pool is open when the high temperature is higher than $20^oC$.

As the pool was closed on Thursday. This means that temperature on Thursday was less than or equal to 20 degree Celsius. We can represent this information in an inequality as:

$30-3d\leq20$

Therefore, the inequality $30-3d\leq 20$ can be used to determine the rate of temperature decrease in degrees Celsius per day, d, from Monday to Thursday.