. The opening balance of one of Jennie's 30-day billing cycles for her credit card was $1220, and it remained that amount for the first 10 days of her billing cycle. She then made a purchase for $470, increasing her balance to $1690, where it remained for the next 10 days. Jennie then made a payment of $350, so her balance for the last 10 days of the billing cycle was $1340. The APR of Jennie's credit card is 33%. What is her periodic interest rate?

Question