In how many ways can a teacher arrange 6 students in the front row of a classroom with a total of 20 students?

If $740 is invested at an interest rate of 11% per year and is compounded continuously, how much will the investment be worth in 7 years? use the continuous compound interest formula a = pert.

Amountain climber starts a climb at an elevation of 453 feet above sea level at his first rest stop he has climbed 162 feet and by his second rest stop he has climbed another 207 feet its getting late in the day so the climber starts his way down if the climber desends 285 feet how much does he need to ascend or descend to return to the original starting point

How do i simply this radical expression?