The supply of generic cheese sandwiches is perfectly elastic, the demand for generic cheese sandwiches is unit elastic, and with no tax on generic cheese sandwiches, the price is $1 million and 240 generic cheese sandwiches a week are bought. Now generic cheese sandwiches are taxed at 20 percent. Discuss tax incidence, tax revenue, and the efficiency of this tax.

Please use thorough wording and graphs so I may understand better, thank you