MCQ for Economics Nov 2008 Paper 1 Question 9

[arvind0708]

9 There are three firms (X, Y and Z) supplying a market. The table shows their supply at four
different prices.
price ($) firm X’s supply firm Y’s supply firm Z’s supply
10 50 40 10
20 60 60 20
30 85 80 35
40 120 100 55
Which price change is required for market supply to double?
A $10 to $20 B $10 to $30 C $20 to $30 D $20 to $40

hOW TO GET THE ANSWER.

 

[Xenon]

Find the market supply at each price. The market supply is given/found by adding the quantity supplied by each individual firm. This gives 100,140, 200 and 275 units at price 10, 20, 35 and 55 respectively. This shows that the market supply increases from 100 to 200 (doubles) when price changes from 10 to 30.
Ans: B