Durell and Earline are married; file a joint return; ad claim dependency exemptions for their two children, ages 5 years and 6 months. They also claim Earline's son rom a previous marriage, age 18, as a dependent. Durell and Earline's combined AGI is $68,000.
a. Compute Durell and Earline's child tax credit.
b. Assume the same facts, except that Durell and Earline's combined AGI is $122,000. Compute their child tax credit.