I know 6% of $3000 is $180
But I don't understand the rest of the question.
The answer is (3,1), hope that helps
Let n be unknown number, then 1/5 of this number is 1/5n. When you add these two numbers, you get

You know that this sum is equal to 24, so

1. Multiply this equation by 5:

2. Solve it:

Answer: n=20, correct choice is B.