Making a long distance call that charges a 2 dollar connection fee and

Hi All,

While this question can certainly be solved algebraically, it can be solved rather easily with a bit of 'brute force' arithmetic and TESTing THE ANSWERS.

The prompt explains two different ways to 'bill' a phone call:
Option 1) A $2 connection fee + $0.03 per minute for the call
Option 2) No connection fee + $0.05 per minute for the call

We're asked for the length of a call that would cost the SAME under each of the above 2 options...

Let's TEST Answer A: 1 hour

Option 1: $2 + (60)(.03) = $2 + $1.80 = $3.80
Option 2: (60)(.05) = $3.00
This two costs are not equal. Eliminate Answer A

It's important to note that as we increase the number of total minutes, Option 2 will increase in cost FASTER than Option 1 will...

Let's TEST Answer C: 2 hours

Option 1: $2 + (120)(.03) = $2 + $3.60 = $5.60
Option 2: (120)(.05) = $6.00
This two costs are not equal. Eliminate Answer C

Looking at these two results, you can see that Option 1 costs more during a 1-hour call and Option 2 costs more during a 2-hour call. At some point - between 1 hour and 2 hours - Option 2 "moved past" Option 1 in total cost, so the point at which the two options was equal MUST have occurred at some point in that range.

Final Answer:
GMAT assassins aren't born, they're made,
Rich