Teddy, Karzan and Karl went to the store to buy candy. Teddy spent $21 on 3 pieces of candy, Karzan spent $63 on 21 pieces of candy, and Karl spent $58 on 20 pieces of candy. Who spent the LEAST per piece of candy?

Two cyclists 84 miles apart start riding toward each other at the same. one cycles 2 times as fast as the other. if they meet 4 hours later, what is the speed (in mi/h) of the faster cyclist?

Thompson and thompson is a steel bolts manufacturing company. their current steel bolts have a mean diameter of 127 millimeters, and a variance of 36. if a random sample of 35 steel bolts is selected, what is the probability that the sample mean would differ from the population mean by greater than 0.5 millimeters? round your answer to four decimal places.

Ab and bc form a right angle at point b. if a= (-3,-1) and b= (4,4) what is the equation of bc?