Please help I've never been more confused

If a =6, what is the value of 2a(3b + 5c)?

The number of chocolate chips in an 18-ounce bag of chocolate chip cookies is approximately normally distributed with a mean of 1252 chips and standard deviation 129 chips. (a) what is the probability that a randomly selected bag contains between 1100 and 1500 chocolate chips, inclusive? (b) what is the probability that a randomly selected bag contains fewer than 1125 chocolate chips? (c) what proportion of bags contains more than 1225 chocolate chips? (d) what is the percentile rank of a bag that contains 1425 chocolate chips?

Use the net as an aid to compute the surface area of the triangular prism. a) 550 m2 b) 614 m2 c) 670 m2 d) 790 m2