Suppose the amount of algae in a pond doubles every 3 hours if the pond initially contains 50 pounds of algae , how much algae will be in the pond after 9 hours

Can someone with this? ! the answer choices are 1, 1.3, 1.45, and 1.9!

Li buys supplies so he can make and sell key chains. he begins to make a profit only after he sells 4 key chains. what point on the graph makes the most sense in this situation?

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?