Donya ran a 3k race at a constant speed in 21 minutes 30 seconds. at this speed, how long does it take her to run 1k?

I'm so close to finishing all these.

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?

Solve the system of equations y= 3/2 - 1, -x+ y =-3