A team of mountain climbers to descend 3600 feet to a camp that was at an altitude of 12,035 feet. At what altitude did they start?​

Me answer number 3plz explain how you do it

Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.

What is the perimeter of trapezoid jklm? + units 2 + + units 9 + units 9 + + units