A traditional unit of length in Japan is the ken (1 ken = 1.97 m). What is the volume of a cylindrical water tank of height 7.17 kens and radius 6.21 kens in cubic kens

V = pi*r^2 * h.

V = 3.14*(6.21)^2 * 7.17 = 868 kens^3.

To calculate the volume of a cylindrical water tank, we need to use the formula:

Volume = π * r^2 * h

Given that the height is 7.17 kens and the radius is 6.21 kens, we can substitute these values into the formula:

Volume = π * (6.21)^2 * 7.17

Now, let's calculate the volume step by step:

1. Calculate the square of the radius:
r^2 = 6.21 * 6.21
r^2 = 38.5641

2. Multiply the square of the radius by the height:
(6.21)^2 * 7.17 = 38.5641 * 7.17 = 276.710197

3. Multiply the result by π (pi) to get the final answer:
Volume = π * 276.710197

Now, to express the volume in cubic kens, we need to divide the result by the conversion factor between cubic meters and cubic kens. The conversion factor between the units is 1 ken = 1.97 m.

So, the final step is to divide the volume by the conversion factor:

Volume = π * 276.710197 / (1.97)^3

Now, you can use a calculator or a math software to substitute the value of π and evaluate the expression to find the volume of the cylindrical water tank in cubic kens.