Let's call the number of toys produced on that day as "x".
According to the given information, the cost of production of each toy was 9 less than twice the number of toys produced. This can be represented as 2x - 9.
The total cost of production on that day was Rs 143. This can be represented as:
Total cost = (cost per toy) * (number of toys)
143 = (2x - 9) * x
143 = 2x^2 - 9x
2x^2 - 9x - 143 = 0
To solve this quadratic equation, we need to use the quadratic formula:
x = (-b ± √(b^2 - 4ac)) / (2a)
where a = 2, b = -9, c = -143
By plugging these values into the quadratic formula, we get:
x = (9 ± √(81 + 1144)) / 4
x = (9 ± √1225) / 4
x = (9 ± 35) / 4
x = (9 + 35) / 4 or x = (9 - 35) / 4
x = 44 / 4 or x = -26 / 4
x = 11 or x = -6.5
Since the number of toys cannot be negative, the industry produced 11 toys on that day.
We can then find the cost per toy:
2x - 9 = 2*11 - 9 = 22 - 9 = 13
So, the cost of production of each toy was Rs 13.