The total number of elements in the power set of a set A containing ‘n’ elements is​

Answer the questions in the attachment. a rescue helicopter is at point a and a rescue boat is at point e. the helicopter pilot spots boats in distress at points d and c,with angles as marked in the diagram. figure abce is a rectangle. the altitude of the rescue helicopter, represented by ae, is 5000 feet.

Isuck at math ; ^; m a student solved this problem and said the answer is 3 feet. chase had a roll of ribbon that contained 7 7/8  feet of ribbon. he cut off one piece that was 3 5/8  feet long and another piece that was 1 1/4  feet from the roll. how much ribbon was left on the roll? is the student's answer reasonable? yes, the answer is reasonable. no, the answer is not reasonable. it should be about 2 feet. no, the answer is not reasonable. it should be about 13 feet. no, the answer is not reasonable. it should be about 4 feet.

Factor the expression using the gcf. the expression 21m−49n factored using the gcf