Determine the amount of the standard deduction allowed for 2018 in the following independent situations. In each case, assume that the taxpayer is the dependent of another taxpayer.
a. Curtis, age 18, has income as follows: $700 interest from a certificate of deposit and $12,200 from repairing cars.
b. Mattie, age 18, has income as follows: $600 cash dividends from a stock investment and $4,700 from handling a paper route.
c. Jason, age 16, has income as follows: $675 interest on a bank savings account
and $800 for painting a neighbor's fence.

d. Ayla, age 15, has income as follows: $400 cash dividends from a stock investment and $500 from grooming pets.
e. Sarah, age 67 and a widow, has income as follows: $500 from a bank savings account and $3,200 from babysitting.