A cylindrical water tank has a base radius of 7 m and a height of 10 m. Water is filled into the tank at a constant rate. After filling the tank completely, 5% of the water leaks out due to a crack at the bottom. The remaining water is transferred into another cylindrical tank whose base radius is 5 m. Find the height of water in the second tank.

Correct option is C

Given
Tank 1: radius = 7 m, height = 10 m
Water leakage = 5%
Tank 2: radius = 5 m
Formula Used
Volume of cylinder = $$\pi r^2 h$$​​
Solution
Initial Volume of Tank 1 =$$\pi \times 7^2 \times 10 = 490\pi$$​​
Water remaining after 5% leak = $$95\% of 490\pi$$​​
Remaining Volume = $$0.95 \times 490\pi = 465.5\pi$$​​
Let the height of water in the second tank be h.
Volume of water in Tank 2 =$$\pi \times 5^2 \times h = 465.5\pi$$​​
​$$25h = 465.5$$​​
h =$$\frac{465.5}{25} = 18.62$$​ m
Final Answer
So the correct answer is (c)