Given a and b are numbers, and a+b=180, which statements also must be true

The probability that a student graduating from suburban state university has student loans to pay off after graduation is .60. if two students are randomly selected from this university, what is the probability that neither of them has student loans to pay off after graduation?

Two angles are complementary. the larger angle is 36 more than the smaller angle. what is the measure of the larger angle?

One file clerk can file 10 folders per minute. a second file clerk can file 11 folders per minute. how many minutes would the two clerks together take to file 672 folders?