Anyone show me how to work these A toll bridge charges SI 50

A toll bridge charges SI .50 for passenger cars and $3.00 for other vehicles. During the daytime 70% of all vehicles crossing the bridge are passenger cars. Consider the next 25 vehicles cross the bridge during a particular daytime period. Let X represent the number of passenger cars among the next 25 vehicles that cross the bridge. What is the expected value of X ? Justify your response Let y be the revenue in tolls generated by the next 25 vehicles that cross the badge. Express near What is the resulting expected toll revenue Y ? We again consider the situation of the previous problem toll bridge charges $1.50 for passenger cars and $3.00 for the vehicles During the daytime 70% of all vehicles crossing the bridge are passenger cars. A transportation Commission observe beings counting vehicles that cross the bridge, and will count until cross the bridge Let Z be the number of trucks that pass before she

Solution

a)

expected value = 25* 0.70 = 17.5

b)

Y = 1.50*x + 3* (25-x)

c)

expected revenue

Y = 1.50 * 17.5 + 3*(25-17.5) = $48.75