Gabe contributes to an employer-sponsored 401(k) plan. For the first 6% of
Gabe's salary, his employer matches 100% of his 401(k) contributions, and
from 6% to 12%, Gabe's employer matches 50% of his 401(k) contributions,
Gabe's salary is $30,000, and last year he contributed $4000 to his 401(k)
plan. What was the total amount that was contributed to his 401(k) last year?