Question

A test has 10 questions. You must answer a total of 7 questions, including exactly 4 of the first 6 questions.
A) In how many ways can you choose 4 of the first 6 questions?
B) How many questions are left after you have answered 4 of the first 6 questions? How many must you still answer?
C) In how many ways can you choose questions to finish the test?
D) How many different ways are there of completing the test (meeting all of its requirements)?
*** note.. I have answered question A

Answer 1

A you are being asked for "6 choose 4" written as \[\binom{6}{4}\] or \[_6C_4\] pr even \[^6C_4\] and computed via \[\binom{6}{4}=\frac{6\times 5}{2}\] cancel first multiply last

Answer 2

and of course now i read the note
the next one is just as easy

Answer 3

How many questions are left after you have answered 4 of the first 6 questions? How many must you still answer? ?