An oil-drilling company knows that it costs $25,000 to sink a test well. if oil is hit, the income for the drilling company will be $825,000. if only natural gas is hit, the income will be $225,000. if nothing is hit, there will be no income. if the probability of hitting oil is 1/40 and if the probability of hitting gas is 1/20, what is the expectation for the drilling company? $

The expectation for the drilling company is $6,875.

Step-by-step explanation:

is the income that is expected in relation to natural gas being hit. There is a 1/20 probability that gas is hit. If gas is hit, the income will be $225,000. So

is the income that is expected in relation to oil being hit. There is a 1/40 probability that oil is hit. If oil is hit, the income will be $825,000. So

25,000 is subtracted from the expectation because it is the cost to sink a test well.

The expectation is:

The expectation for the drilling company is $6,875.

256π units²   (answer b)

step-by-step explanation:

the formula for the surface area of a sphere of radius r

is             a = 4πr²

and so, if r = 8 units, then the surface area is:

a = 4π(8 units)² = 256π units²   (answer b)