We'll start by changing the 14% into the decimal form by moving the decimal two places to the left. That would make 14% = 0.14.
Next, multiply all the variables together.
3000 x 0.14 x 6= 2520
This shows that they'll earn $2520 within 6 years at 14% interest.
With the $3,000 principal and add the interest earned $2520
3000 + 2520 = 5520
At the end of 6 years, there will be $5,520 in the account.