Pls say fast :( its my online test

Me find the measure to side c and the process to solve the problem you appreciate it : )

You drop a rubber ball off the roof of a 50 meter high building onto a paved parking lot. it bounces back up with every bounce, but not quite all the way back up to you. after the first bounce it bounces back only 80 percent of the distance it was dropped from. the pattern continues, meaning after every bounce it comes up to just 80 percent of the previous maximum height. so if before the first bounce the height is 50 meters, what height does the ball reach after the fifth bounce? round your answer to one decimal place and chose the correct response from the choices below:

Alicia puts $400 in a bank account. each year the account earns 5% simple interest. how much money will be in her bank account in six months?