A rock climber climbs 75 feet in the first half-hour of climbing. In each succeeding half-hour, the climber achieves only 90% of the height achieved in the previous half-hour. Find the total height climbed.

Handsome jack is buying a pony made of diamonds. the price of the pony is p dollars, and jack also has to pay a 25% diamond pony tax. which of the following expressions could represent how much jack pays in total for the pony?