Over the course of a year, a tractor trailer commutes 160,000 miles across America. If the trucker changes his oil every 10,000 miles, and he starts the year with a fresh oil
change, how many times will he change the oil in a year?

There is some inforrmation that is missing in this question. It should read:

A container holds 50 electronic components, of which 10 are defective. If 6 components are drawn at random from the container, the probability that at least 4 are not defective is . If 8 components are drawn at random from the container, the probability that exactly 3 of them are defective is .

Answers

Part 1.   0.02

Part 2.  0.0375

Explanation

The probability is a chance of an event happening. It is calculated as;

probability = (Number of favourable outcome)/(Number of available outcome)

Part 1

6 are chosen at random. If 4 are not defective, then 2 are defective.

P(at least 4 are not defective) = 4/40 × 2/10

                                               = 1/10 ×1/5

                                               = 1/50

                                                = 0.02

Part 2

8 are chosen at random. If 3 are defective, the 5 are not defective.  

P(3 are defective) = 3/40 × 5/10  

                            = 15/400

                            = 3/80

                           = 0.0375

Step-by-step explanation: