Please, I need it within 20 minutes. solve and post the value ASAP

3. "Machine A costs $24,000 to purchase and is worth $9,000 in 4 years at the end of its service life. Machine B costs $20,000 to purchase and is worth $3,000 in 4 years at the end of its service life. Assume that these machines are needed for 4 years (required service period). Each machine can be repurchased at the same price in the future, and assume the annual maintenance cost of each machine is negligible. Use 11% annual interest rate.
Compute the Annual Equivalent Cost (AEC) of each machine and enter the AEC of the machine that should be purchased as a positive number."