In a market, demand is $p = 28 - 2x$ and supply is $p = 4 + x$. What is the total surplus, consumer plus producer, at equilibrium?

Explanation

1. 01

   Equilibrium: $28 - 2x = 4 + x$, so $x_0 = 8$ and $p_0 = 12$.

2. 02

   CS $= \frac{1}{2} \times 8 \times 16 = 64$ and PS $= \frac{1}{2} \times 8 \times 8 = 32$: together $96$ rupees.