What is probability to chose committee of 4 people if there are 10 men and 6 women and we require that we need 3 men and 1 woman be in committee?

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?