Tap A can fill an empty tank completely in 24 minutes. Tap B can empty the full tank completely in 40 minutes. Both taps are turned on at the same time when the tank is empty. How many minutes does it take to fill the tank completely?
Show Worked Solution
Worked Solution
Step 1: Tap A fills 1/24 of the tank each minute.
Step 2: Tap B drains 1/40 of the tank each minute.
Step 3: Net fill rate per minute = 1/24 − 1/40.
Step 4: Find a common denominator: LCD of 24 and 40 is 120.
1/24 = 5/120, and 1/40 = 3/120.
Step 5: Net fill rate = 5/120 − 3/120 = 2/120 = 1/60 of the tank per minute.
Step 6: Time to fill the full tank = 1 ÷ (1/60) = 60 minutes.
Correct answer: 60 minutes
Want more questions like this? Superholic Lab has 10,000+ MOE-aligned questions with full worked solutions.
Start Free Trial — 7 Days Free