What is the consumers' surplus at the market's…

What is the consumers' surplus at the market's equilibrium?

Question 36

MediumOriginal question

In a weekly vegetable market, the demand for a crate of tomatoes is $p = 90 - 3x$ and the supply is $p = 10 + x$ , where $x$ is the number of crates and $p$ the price in rupees.

What is the consumers' surplus at the market's equilibrium?

₹200Correct answerYour answer₹300Correct answerYour answer₹600Correct answerYour answer₹1,200Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer C

Correct answer: C

$CS = \int_0^{20}(90 - 3x)\,dx - 30 \times 20 = (1{,}800 - 600) - 600$ .
₹600, the triangle $\frac{1}{2} \times 20 \times (90 - 30)$ .

Worth noting

₹1,200 is what buyers would be willing to pay in all; the surplus subtracts the ₹600 they do pay.

Concept: Consumers' surplus at equilibrium
Typical timeTypical: 120 s
Your timeYours: —

The rule this testsMarket equilibrium

Practise this chapter →

Ten questions from Consumer & Producer Surplus, at your own pace.

Practise this chapter →

Ten questions from Consumer & Producer Surplus, at your own pace.

What is the consumers' surplus at the market's equilibrium?

Question 36

Explanation