The problem asks for the cost to fill 90% of a chocolate box shaped like a regular right pyramid with a square base.
$A = s^2 = (10 \text{ cm})^2 = 100 \text{ cm}^2$
$V = \frac{1}{3} \times \text{Base Area} \times \text{Height}$
$V = \frac{1}{3} \times 100 \text{ cm}^2 \times 12 \text{ cm} = \frac{1200}{3} \text{ cm}^3 = 400 \text{ cm}^3$
$V_{fill} = 0.90 \times V = 0.90 \times 400 \text{ cm}^3 = 360 \text{ cm}^3$
Finally, calculate the total cost based on the volume to be filled and the cost per cubic centimeter.
$ \text{Cost} = 360 \text{ cm}^3 \times \text{₹}0.50/\text{cm}^3 = \text{₹}180 $
The cost of chocolate to fill one such box up to 90% capacity is ₹180.