A barrel contained 60 gallons of water. Water leaked out of the barrel at a rate of 5 gallons every 3 days. how may day would it take to run out of water if we added 15 gallons of water on the sixth day

It would take 45 days for all of the water to run out.

Step-by-step explanation:

Every 3 days, the barrel leaks 5 gallons. After the first three days, it would be 55 gallons. After 6 days, it would have been 50 gallons, but 15 gallons of water was added (bringing it up to 65 gallons). Going in increments of 3 (for 3 days), count backwards by 5. (Ex. 9 = 60, 12 = 55, 15 = 50, etc.) The barrel is completely empty after 45 dayd.