Answer:
12
Step-by-step explanation:
1/3 divide by 4
Take the reciprocal and get 3 times 4
Gives you 12.
Answer:
This test batch can be chosen in 2380 ways
Step-by-step explanation:
The order in which the batteries are chosen is not important. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

In how many ways can this test batch be chosen?
4 batteries from a set of 17. So

This test batch can be chosen in 2380 ways
1st month +450
-60 x 4 months = -240
6th month + 125
Total: 450 - 240 + 125 = $335 profit