- CFA Exams
- CFA Level I Exam
- Topic 2. Economics
- Learning Module 8. Topics in Demand and Supply Analysis
- Subject 2. Elasticities of Demand
CFA Practice Question
Suppose that the initial price of pizza is $2 and the initial quantity demanded is 100 pizzas. If the price increases to $2.20 and the quantity demanded falls to 90, what is the price elasticity of demand (in absolute value)?
B. 1
C. 1.10
A. 10
B. 1
C. 1.10
Correct Answer: C
Based on the formula: [(100 - 90)/((100 + 90)/2)] / [(2 - 2.2)/((2 + 2.2)/2)] = 1.1.
User Contributed Comments 9
User | Comment |
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ridone | be careful! check which is quantity and which is price. |
TUFF | here you don't have to round-up the answer to neither significant figures nor decimal places. the word is absolute. that is actual. |
Korny | Why the answer is not 1.0? Can anyone please explain? |
leftcoast | Korny - because the slope of the demand curve is unknown, we can't calculate the elasticity of a specific point. Therefore we calculate the "arc elasticity," which is the elasticity between two price points. Answer above is just plugging the numbers into the formula: [(Change in quantity)/(average quantity)]/[(change in price)/(average price)] |
plablonde1 | how would it be clear in a question like this as to what the slope of the demand curve is? i'm struggling to understand when i would be calculating arc elasticity vs elasticity of a specific point |
kingirm | ????? why sum up and divide into 2 the beginning and ending figures ??? |
IatLs | Thanks for the explanation leftcoast. |
Andmlk | The slope is actually negative if quantity decreases when prices rises. So I really do not understand why we calculate this Arc with mid points. |
ctschro | ty leftcoast |