$3,000 balance, 21% rate, $1,500 payment, adjusted balance method

To determine the adjusted balance method for calculating interest, follow these steps:

Step 1: Start with the beginning balance. In this case, the beginning balance is $3,000.

Step 2: Subtract any payments made during the billing cycle. In this case, the payment is $1,500. Therefore, subtract $1,500 from the beginning balance:

$3,000 - $1,500 = $1,500

Step 3: Compute the adjusted balance by considering any additional charges or credits during the billing cycle. Since the question does not mention any additional charges or credits, there are none to include. The adjusted balance remains $1,500.

Step 4: Calculate the interest charge. The interest rate is given as 21%. To find the interest charge using the adjusted balance method, multiply the adjusted balance by the interest rate:

$1,500 * 0.21 = $315

The interest charge using the adjusted balance method would be $315.