How much income would an accrual basis taxpayer report in 2021in each of the following situations?
a. Toby's Termite Services Inc. provides monthly pest control on a contract basis. Toby sells a 1-year contract for $600 and a 2-year contract for $1,080. In October, Toby sells 10 1-year contracts and 5 two-year contracts.

b. John's Tractor Sales receives a $150 deposit from a customer for a new tractor that the customer orders in December. The tractor arrives the following February, at which time the customer pays the remaining $9,800 of the agreed-upon sales price.
c. A customer of First Financial Lending sends First Financial two $600 checks in December in payment of December and January interest on a loan.

d. First Financial Lending receives interest payments totaling $8,400 in January 2022in payment of December 2021interest on loans.