Answer:
24t + 270 gallons
Step-by-step explanation:
Given that :
Addition rate 1 = 15 gallons per minute
Addition rate 2 = 9 gallons per minute
Total time spent adding water = half an hour = 30 minutes = 0.5 hour
Time spent adding water at faster rate = t
Time spent addition water at slower rate = (30 - t)
Total number of water added to the pool :
Amount of water added = addition rate * time
Hence,
Amount of water added at faster rate :
(15 gal / min) * t = 15t gallons
Amount added at slower rate :
(9 gal / min) * (30 - t) = (270 - 9t) gallons
Total amount of water added to the pool:
15t gallons + (270 - 9t)gallons
15t + 270 + 9t
24t + 270 gallons