ISI 2011 doubt

[shiva]

Can any of you please explain on how to solve this question

[Asd1995]

Pareto optimality condition:

MRS(i,j) where i,j are different goods for each consumer are the same. (You should check that the utility function is concave first though)

Hence Ci/Cj for each person is equal and equals wi/wj

Clearly the given allocation satisfies the above criteria.