If the radius of a circle with center 0 is 15.5, and the measure of angle aob is 90, what is the length of arc ab?
7.75
7.75π
10
10π

i'm stupid when it comes to math.
surprised i made it here.

Ian is in training for a national hot dog eating contest on the 4th of july. on his first day of training, he eats 4 hot dogs. each day, he plans to eat 110% of the number of hot dogs he ate the previous day. write an explicit formula that could be used to find the number of hot dogs ian will eat on any particular day.

The length of time it takes to find a parking space at 9 a.m. follows a normal distribution with a mean of 5 minutes and a standard deviation of 2 minutes. find the probability that it takes at least 8 minutes to find a parking space. (round your answer to four decimal places.)

What is the total surface area of the square pyramid