If we set the unknown distance (in miles) as x, then we set up an equation according to the data, we can solve for x.
Time taken to go to resort : x/48
Time taken to return : x/40
Total time = x/48+x/40 = 11
Solve for x
common multiple between 48 and 40 = 240
so
5x/240 + 6x/240 = 11
(5x+6x)/240 = 11
11x = 11*240, => x=240
Distance from home to resort is 240 miles