<p>Demand function in your question is given as</p>

<p>Q=12-3P</p>

<p>In order to find consumer surplus,we first find inverse demand function from it</p>

<p>Q=12-3P
12-Q=3P
12/3-Q/3=P
4-Q/3=P or
P=4-Q/3</p>

<p>At P = 3 ,from inverse demand function, we get Q= 3</p>

<p>Since intercept in the inverse demand function is 4 and base is 3,we can calculate consumer surplus by using the formula for area of a triangle as ab/2 i.e 4x3/2=6 </p>

<p>Similarly,when price falls to 1,we get value of Q=9</p>

<p>Here,area of triangle becomes 9x4/2=18,which is the new consumer surplus</p>

<p>Subtracting 6 from 18, we get the change in consumer surplus as 12</p>

<p>So the answer to your question is 12.</p>

CC BY-SA 3.0
2016-05-12T11:06:41.343Z
2016-05-12T11:06:41.343Z
Glitteringstar
<p>Suppose the demand function is 12-3p=q and price falls from 3 to 1. How much is the change in consumer surplus?</p>

<mathematical-economics>
The question is related to topic consumer surplus
user8244
# The question is related to topic consumer surplus

(Asked by: username_0 on 2016-05-12)

Suppose the demand function is 12-3p=q and price falls from 3 to 1. How much is the change in consumer surplus?

**Tags:** mathematical-economics

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## 1 answers

### Answer by username_1 on 2016-05-12. Score: 1 | Accepted answer

Demand function in your question is given as

Q=12-3P

In order to find consumer surplus,we first find inverse demand function from it

Q=12-3P
12-Q=3P
12/3-Q/3=P
4-Q/3=P or
P=4-Q/3

At P = 3 ,from inverse demand function, we get Q= 3

Since intercept in the inverse demand function is 4 and base is 3,we can calculate consumer surplus by using the formula for area of a triangle as ab/2 i.e 4x3/2=6

Similarly,when price falls to 1,we get value of Q=9

Here,area of triangle becomes 9x4/2=18,which is the new consumer surplus

Subtracting 6 from 18, we get the change in consumer surplus as 12

So the answer to your question is 12.


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