Monica built a porch that contained 2 different colors of bricks to create a pattern. she purchased the red bricks for $7 each and the gray bricks for $4 each. write a system to find out how many red bricks monica purchased if she spent $193 on 40 bricks?

a. what is the system that models this situation?
equation #1:
equation #2:

b. how many red bricks did monica purchase?

An engineer is going to redesign an ejection seat for an airplane. the seat was designed for pilots weighing between 120 lb and 161 lb. the new population of pilots has normally distributed weights with a mean of 125 lb and a standard deviation of 28.1 lb. a)if a pilot is randomly selected, find the probability that his weight is between 120 lb and 161 lb.the probability is approximately? b. if 36 different pilots are randomly selected, find the probability that their mean weight is between 120 lb and 161 lb. the probability is approximately? c. when redesigning the ejection seat, which probability is more relevant? . part (b) because the seat performance for a single pilot is more important. b. part (b) because the seat performance for a sample of pilots is more important. c. part (a) because the seat performance for a sample of pilots is more important. d. part (a) because the seat performance for a single pilot is more important.