HELP PLS I'LL GIVE BRAINLIEST

15m is what percent of 60m; 3m; 30m; 1.5 km? the last one is km not m

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”?

Which of the following is an irrational number