Ablueberry muffin recipe calls for 1 3/4 cups of sugar. how many cups of sugar would be needed to make the muffin recipe 3 times?

1 3/4 cups of sugar = 7/4 cups of sugar;
3 x (7/4) = 21/4 = 5 1/4 cups of sugar to make the muffin recipe 3 times;

The probability density function (pdf) is one that goes (0,0) to (1,1) in a straight line, and drops back to zero (in a straight line) from 1 to 2.
<=120 hours means x<=1.2
(a) Area under the pdf from 0 to 1.2 equals
P(X<=1.2)=0.5 (from 0 to1) + (1+0.8)/2*0.2=0.5+.18=0.68
(b) area between 50 and 100 hours means 0.5<=x<=1
=(3/4)(0.5)
=0.375