The total cost of making $x$ units is $C(x) = x^{3} - 6x^{2} + 20x + 300$ rupees. What is the marginal cost when 5 units are made?

₹20Correct answerYour answer₹34Correct answerYour answer₹35Correct answerYour answer₹375Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer C

Correct answer: C

Marginal cost is the derivative of total cost: $MC = C'(x) = 3x^{2} - 12x + 20$ .
$C'(5) = 75 - 60 + 20 = 35$ rupees.

Worth noting

₹375 is the total cost of the 5 units, $C(5)$ .

Ten questions from Rate of Change, Marginal Cost & Revenue, at your own pace.

Ten questions from Rate of Change, Marginal Cost & Revenue, at your own pace.

The total cost of making xxx units is C(x)=x3−6x2+20x+300C(x) = x^{3} - 6x^{2} + 20x + 300C(x)=x3−6x2+20x+300 rupees. What is the marginal cost when 5 units are made?