Cost of production of each unit of electricity is 3 less than twice the total number of units produced. If the total cost of production is ₹ 20, find the number of units of electricity produced.
4
Let the number of units of electricity produced be x.
Then, cost of production of each unit = ₹ (2x−3)
Total cost of production = ₹ x(2x−3)
x(2x−3)=20
2x2–3x–20=0
2x2−8x+5x–20=0
2x(x−4)+5(x−4)=0
(2x+5)(x−4)=0
x = -2.5 or x = 4
As number of units cannot be negative,
Number of electricity units produced = 4