Borrow 300,000 yuan, with a monthly interest rate of 7,500 yuan and an annualized annual interest rate of 30%.

Borrow 300,000 yuan, and the monthly interest rate is 7,500 yuan, and the monthly interest rate is 7,500/300,000 = 2.5%.

The annual interest rate is 12*2.5%=30%.

The annual interest rate exceeds the interest range stipulated by the state and belongs to usury.