A new law requires that 12% of an individual's income be invested in the stock market. Your accounts show that you need to put $420 in the stock market this year. How much did you earn this year.

A $5,040 B $350 C $504 * * D $3,500

If you need to put $420 this year and the law requires 12% of the income to be invested in the stock market, then you earned:

$240/0.12 = $3500 this year

So, you earned a total of $3,500 this with 12% of it invested in the stock market which is 12% of your total earnings leaving you with just $3,080