Mr$.$ Howard makes contributions of C $$ at the end of each quarter for

one year and a half. The fund applies an APR of $12\%.$ With the

capital obtained, he satisfies the $25\%$ of the price of a car, funding

the rest over $3$ years with a financial institution that charges an

effective annual interest rate of $16\%.$ The financial institution will

charge him monthly with the following scheme:

$-$ For the first year, $200$ per month $($at the end$).$

$-$ For the second year, $300$ a month $($at the end$).$

$-$ For the third year, $400$ a month $($at the end$).$

Calculate C or PMT$.$