The answer to the selected problem is: that is a linear equation.
Im not 100% sure, but I would say that the answer is A. because the magnet must be strong enough to hold the switch in place, and keep the circuit connected
20 = 8 + v equals v = 12.
First, subtract 8 from both sides. Your problem should look like: 20 - 8 = v
Second, simplify 20 - 8 to get 12. Your problem should look like: 12 = v.
Third, switch sides to get v = 12, which is the correct answer.
Since we already know that there is a 25% chance to guess the correct answer to a multiple choice question, all we have to do is multiply .25 and 68 to get the expected amount of answers a student can possibly guess. We multiply .25 since it is the decimal form of 25% and 68 is our total questions.
.25 x 68 = 17
Therefore, a student can expect to guess 17 answers correct on a test with 68 multiple choice questions.
