The answer is c)4 bc the four scores under 70 are 69, 65, 63 and 58
For this case we have the following functions:

We must find
. By definition of compound functions we have to:

So:
Taking into account that:

Different signs are subtracted and the major sign is placed.

Finally we have to:

Answer:

Sometimes because it might not always be true
Answer:
Step-by-step explanation: