Hi, please see the attaced file from the GMAC practice GMAT test. Why can 48 be chosen as the amount of work. When another number, e.g. 50, were chosen, the outcome would have been completely different, correct?

Sorry I don't have an answer but want to express I'm also having the same issue on similar problems and looking forward to the real explanation!

Some question explanations say to sub in arbitrary values, and others say to solve algebraically for similar questions. How are we supposed to know when to use which method?? It's very frustrating...

it is not necessary to make any assumptions or chose any numbers ...

crew A: 1 house / 8 hours = 1/8 house/hr

crew B: 1/6 house/hr
crew C: 1/6 house/r

A,B, & C together: 1/8 + 1/6 + 1/6 = 22/48 house/hr

rate = work/time

time = work / rate = (1 house)/(22/48 house/hr) = 48/22 hours = 24/11 hours

2 2/11 hours


Veritas Help

Oh, IIIIIIIIIII see. Thanks!