From 5 red and 6 yellow balls 6 balls are drawn without replacement .x shows number of red balls. then find probability distribution and mean and variance

Two technicians are discussing how to test a car's exhaust by holding a small piece of paper within an inch of the tailpipe mouth. technician a says that if the paper is vibrating due to a "puffing" output from the tailpipe, this signals a smoothly running engine. technician b says that if the paper is being drawn toward the tailpipe, this could indicate burned exhaust valves. who is correct? a. technician b b. both technicians a and b c. technician a d. neither technicians a or b

Iknow this isn't a question, but is there someway to ask a question under public safety or is there no category for it? i don't know if i'm overlooking it or not.

Which food would provide you with the most calcium?