A bowl contains 15 red balls, 20 green balls and 12 blue balls. A woman selects balls at random without looking at them. How many balls must she select to be sure of having at least three balls of the same color?

Aseries piping system conveys methyl alcohol. the system consists of 70 m of 1- nominal pipe follow by 50 m of 2-nominal pipe, both schedule 40 commercial steel. the 1-nominal pipe contains 3 90° elbows (regular) anda fully open gate valve, all threaded. the pressure drop through the system is 150 kpa. determine the volume flow rate through the system that is horizontally laid.