Of the students who tool English in a certain school one year, 60% of them took History, 30% of them took Biology, and 10% took both History and Biology. One of the students is chosen at random.
a) Find the probability that the student took neither History nor Biology
b) Given that the student took exactly one of History and Biology, find the probability it was History

An airplane consumes fuel at a constant rate while flying through clear skies, and it consumes fuel at a rate of 64 gallons per minute while flying through rain clouds. let c represent the number of minutes the plane can fly through clear skies and r represent the number of minutes the plane can fly through rain clouds without consuming all of its fuel. 56c+64r < 900056c+64r< 9000 according to the inequality, at what rate does the airplane consume fuel while flying through clear skies, and how much fuel does it have before takeoff? the airplane consumes fuel at a rate of gallons per minute while flying through clear skies, and it has gallons of fuel before takeoff. does the airplane have enough fuel to fly for 60 minutes through clear skies and 90 minutes through rain clouds?

Plz hurry evaluate the expression a+b where a=8 and b=19

Find the missing dimension extra points