Answer:
14y-13y² is the answer. sorry for dirty handwriting
35 x 20 dollars= 700 dollars. Total cost of all tickets equals 700 dollars
New pump:
5 hours = 1 pool
1 hour = 1/5 pool
Old pump:
15h = 1 pool
1h = 1/15 pool
If both work together
1h = 1/5 + 1/15 = 4/15 pool
4/15 pool = 1 hour
1/15 pool = 1/4 hour
15/15 pool = 1/4 x 15
1 pool = 3.75 hours or 3 hours 45 mins