Posted by luis on .
An oildrilling company knows that it costs $25,000 to sink a test well. If oil is hit, the income for the drilling company will be $375,000. If only natural gas is hit, the income will be $165,000. 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?

Math 
Reiny,
Just about the same question here, just change the numbers
http://www.jiskha.com/display.cgi?id=1362276660