Jai bought a helmet and a pair of skates. The helmet cost £40.
He sold both items for £172.
Jai made a 135% profit on the cost of the helmet and a 60% profit on the total cost.
What was the percentage profit on the skates?
Give your answer to 1 decimal place.

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?

What are the solutions of the system? y = x^2 + 2x +3y = 4x - 2a. (-1, -6) and (-3, -14)b. (-1, 10) and (3, -6)c. no solutiond. (-1, -6) and (3, 10)

Awindow washer cleans 42 windows in 2 hours. at this rate, how many windows did he clean in 180 minutes.