Even i was caught in the trap of answer A.
I am always cautious while marking (A) as my answer. Not because the probability of it being the answer is low, but because if the question has a trap people could fall for, then the question maker will set (A) as that particular lucrative option. (Hell, I do that when I make questions! Kind of a bait!) So I like to double check especially if it seems too easy.
The logic of (555 - x)/y was perfectly valid. The only missing point was that these are the (n -1) additional minutes. You did not account for the 1st minute. So total time will be (555 - x)/y + 1 which is the same as option (C): (555 - x + y)/y
And yes, parentheses will definitely be there in the exam in such a question. 555 - x + y/y = 555 - x + 1 (Since it didn't make any sense here, it was obvious that there are parentheses in the options). Rest assured, there will not be any ambiguity in the actual exam.
Veritas Prep | GMAT Instructor
Veritas Prep GMAT course is coming to India. Enroll in our weeklong Immersion Course that starts March 29!
Veritas Prep Reviews