10x10^4 written as a single power

Aladder that is 20 ft. long against the side of a building. f the angle formed between the ladder and the ground is 75 degrees, how far is the bottom of the ladder from the base of the building?

From a group of 10 men and 8 women, 5 people are to be selected for a committee so that at least 4 men are on the committee. howmany ways can it be done?

Abox of chocolates cost $7 which equation relates the number of boxes sold parentheses x parentheses and total cost of the boxes sold parentheses y parentheses