Can someone please help

Measures of the angle of r, 31 s (x+4) t (3x+9)

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”?

Shannon drove for 540 minutes. if she traveled 65 miles per hour, how many total miles did she travel?