Grady received $8,440 of Social Security benefits this year. Grady also reported salary and interest income this year. What amount of the benefits must Grady include in his gross income under the following five independent situations?

a. Grady files single and reports salary of $12,700 and interest income of $310.

b. Grady files single and reports salary of $22,660 and interest income of $660.

c. Grady files married joint and reports salary of $76,200 and interest income of $560.

d. Grady files married joint and reports salary of $44,000 and interest income of $760.

e. Grady files married separate and reports salary of $22,660 and interest income of $660.