If you look at the MEP range chart there are 2 sets of curves...range WITH 45min reserve at 45% power and range with no reserve.

For this question you are required to find the range with reserve (left hand set of curves) at economic cruise...and here's the gotcha...look at the top right of the graph, they attach names to the % power settings:
75% high speed
65% economy
45% long range
So, you need to enter the chart at 11000ft....across to the 65% power curve....range 760NAM...now correct for temperature (-8nm) and you get the answer 752nm.