There are 40 tourists and each tent can hold 8 people so, the required number of tents = $\frac{40}{8} = 5$

Base area of each person (A1) = $\text{6ft x 3ft}$

Total base area of each tent (A) = $\text{A}_1 \text{x 8}$

$= \text{6 x 3 x 8 ft}^2$

Given tents have a square base so, the base area can be calculated as $\text{a}^2$ where $\text{a}$ is the length of the base.

$\text{or, a}^2 \text{ = 6 x 3 x 8}$

$\text{or, a}^2 \text{ = 144}$

$\therefore \text{a = 12 ft}$

Volume occupied by each person (V1) = $\text{48 cu.ft}$

Total volume of each tent (V) =  $\text{V}_1 \text{x 8}$

$= \text{48 x 8 cu.ft}$

Volume of a square-based pyramid can be calculated as $\frac{1}{3}\text{a}^2\text{h}$ where $\text{h}$ is the perpendicular height of the pyramid.

$\frac{1}{3} \text{a}^2\text{h } \text{= 48 x 8}$

$\text{or, 12 x 12 x h = 3 x 48 x 8}$

$\text{or, 144 x h = 1152}$

Let $\text{l}$ be the slant height of the pyramid then

$\text{l} = \sqrt{ \left ( \frac{a}{2} \right)^2 + h^2}$

$\text{or, l = } \sqrt{ \left ( \frac{12}{2} \right )^2 + 8^2}$

$\therefore \text{l = 10 ft}$

Now,

The required area of the square-based pyramid tent is $\text{CSA = 2al}$

$\text{or, CSA = 2 x 12 x 10}$

$\therefore \text{ CSA = 240 ft}^2$

Required total area of the tent $\text{= 5 x 240 = 1200 ft}^2$

The required total cost of the tent if it costs Rs. 560 per ft2 then $\text{Cost = 560 x 1200 = Rs 672 000}$

Hence, the required total cost of all the tents at the given rate is Rs 672 000.