A physics exam consists of 9 multiple-choice questions and 6 open-ended problems in which all work must be shown. If an examinee must answer 6 of the multiple-choice questions and 2 of the open-ended problems, in how many ways can the questions and problems be chosen?

The questions and problem can be chosen in 1260 ways.

Step-by-step explanation:

Given that, a physics exam consists of 6 open-ended problem and  9 multiple choice questions.

The order of choosing does not matter.

So,we use combination to find ways.

The ways to choose  6 multiple choice from 9 is=

                                                                              =84

The ways to 2 open-ended question from 6  is=

                                                                             =15

Since pick 6 multiple choice out of 9 and 2 open-ended question out of 6 both are independent we have multiply both to find required ways.

Total number of ways is =(84×15)

                                        =1260.

it is a. 4.2 because 7.6-3.4 gets the remaining length of 4.2. i might be wrong but i am pretty sure this is the answer.