Welcome to this year’s first edition of Workbook Wednesdays, where we offer our readers a shot at one of Manhattan GMAT’s ‘challenge problems,’ the caliber of problem you’ll see if you’re scoring above 700 on the GMAT exam. Check back with us on Thursday when we’ll work through the answer!
Question
One smurf and one elf can build a treehouse together in two hours, but the smurf would need the help of two fairies in order to complete the same job in the same amount of time. If one elf and one fairy worked together, it would take them four hours to build the treehouse. Assuming that work rates for smurfs, elves, and fairies remain constant, how many hours would it take one smurf, one elf, and one fairy, working together, to build the treehouse?
- (A) 5/7
- (B) 1
- (C) 10/7
- (D) 12/7
- (E) 22/7
