Perfect information

Dear Sir,

Please could you clarify the below point for me.
In the September 2016 exam there is the following question:

19: The human resources department has offered to undertake some research to help Mylo to predict the number of employees who will require lunch in the cafeteria each day. This information will allow Mylo to prepare an accurate number of lunches each day.
What is the maximum amount which Mylo would be willing to pay for this information (to the nearest whole $?

Mark scheme is as follows:

Expected value with perfect information = (0·15 x $1,170) + (0·30 x $1,612) + (0·40 x $2,015) + (0·15 x $2,496) = $1,839·50
Expected value without perfect information would be the highest of the expected values for the supply levels = $1,648·25 (at a supply level of 775 lunches).

So I understand the calculation for perfect information (best outcomes times by the probability of that outcome) what I don’t understand is the figure for ‘without perfect information’. I can see its been done based on supply of 775 lunches to reach the figure but I don’t understand why? Why has that level of supply been chosen?

Thanks