please answer in 25 min

A couple took out a $400,000.00 mortgage ten years ago. The original terms called for 30 years of monthly payments at a 4% APR. They have made all payments over the last ten years and are considering re-financing their mortgage. The couple has been offered a chance to re-finance their mortgage balance at the lower rate of 3.60\% APR with monthly compounding. If they decide to make monthly payments of $1,817.33, how long will it take them to pay down their mortgage? 22.37 years 26.11 years 24.84 years None of the above 20.43 years