or
or
Let's call the capacity of the tank "C" liters. Initially, the tank is 40% full of water, which means it contains 0.4C liters of water. When 9 liters of water are removed, it becomes 1/4 full, which means it contains (1/4)C liters of water.
We can set up an equation using this information:
0.4C - 9 = (1/4)C
Now, let's solve for C:
0.4C - 9 = (1/4)C
Multiply both sides of the equation by 4 to eliminate fractions:
1.6C - 36 = C
Subtract C from both sides:
0.6C - 36 = 0
Now, add 36 to both sides:
0.6C = 36
Finally, divide by 0.6 to find the capacity of the tank:
C = 36 / 0.6 = 60
So, the capacity of the tank is 60 liters.
