XAT 2010

Total population = 70000

Average consumer expenditure on Roses and carnations = 47.4

Total expenditure on both carnations and roses = 47.4*70000

                                                                       = 3318000

Given total expenditure on roses = 1136916

So the total expenditure on carnations = 3318000 - 1136916

                                                           = 2181084

Sales of carnations in January = 13848 dozens

Price of carnation  per dozen  in January =2181084/13848

                                                              = 157.5 

Similarly In December 

Average consumer expenditure on Roses and carnations = 56.4

Total expenditure on both carnations and roses = 56.4*70000

                                                                       = 3948000

Given total expenditure on roses = 977688

So the total expenditure on carnations = 3948000 - 977688

                                                           = 2970312

Sales of carnations  = 18859 dozens

Price of carnation  per dozen  in January =2970312/18859

                                                              = 157.5

Therefore the price did not change

Hence E is the correct answer