Answer: A) 1260
Step-by-step explanation:
We know that the number of combinations of n things taking r at a time is given by :-
Given : Total multiple-choice questions = 9
Total open-ended problems=6
If an examine must answer 6 of the multiple-choice questions and 4 of the open-ended problems ,
No. of ways to answer 6 multiple-choice questions
=
No. of ways to answer 4 open-ended problems
=
Then by using the Fundamental principal of counting the number of ways can the questions and problems be chosen = No. of ways to answer 6 multiple-choice questions x No. of ways to answer 4 open-ended problems
=
Hence, the correct answer is option A) 1260