Answer:
11 hours
Step-by-step explanation:
Setting up a system of equations and using the substitution method will give you the number of hours used by each tap. Let a = time for tap A and b = time for tap B:
a + b = 12 (A and B fill a tank in 12 hours)
a = b - 10 (tap A takes 10 hours less than tap B)
Substitute 'b - 10' for 'a' in the first equation:
b - 10 + b = 12
Combine like terms: 2b - 10 = 12
Add 10 to both sides: 2b - 10 + 10 = 12 + 10 or 2b = 22
Divide by 2: 2b/2 = 22/2
Solve for b: b = 11 hours
