HELP timed thank you

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”?

12 out of 30 people chose their favourite colour as blue caculate the angle you would use for blue on a pie chart

Select the correct answer what is the 10th term of the geometric sequence 3,6, 12, 24,48 a. 512 b. 3,072 c. 768 d. 1,536