First, calculate the loan interest rate.

Formula loan amount = monthly repayment amount *[ 1-( 1+ monthly interest rate)-repayment months]/monthly interest rate.

300000 = 2946 * [1-(1+monthly interest rate)-120]/ monthly interest rate

Monthly interest rate =0.27944%

Annual interest rate =3.35327%

Calculate the remaining principal after the 2.60 period.

The formula residual principal = monthly repayment amount *[ 1-( 1+ monthly interest rate)-(remaining months-1)]/ monthly interest rate.

Residual principal = 2946 * [1-(1+0.27944%)-59]/0.27944%.

Residual principal =160,036.15 yuan.

Three. Calculate the one-time repayment amount after 60 installments.

Formula lump-sum repayment amount = {loan amount-monthly repayment amount *[ 1-( 1+ monthly interest rate)-months paid]/monthly interest rate} * (months paid+1)

One-time repayment amount = {300000-2946 * [1-(1+0.27944%)-60]/0.27944%} * (1.27944%) 665438+

One-time repayment amount = 162982.438+05 yuan.

Results:

The remaining principal after the 60th installment is160,036.15 yuan; After 60 installments, the loan can be paid off by one-time repayment of162,982.5438+05 yuan.

Paying off the loan in advance can save interest 13777.85 yuan.