Hi AAPL,

We're told that Joe must travel a total of 225 kilometers to visit his aunt. He rides his bike 5 kilometers to the bus station, travels by bus to the train station, then takes the train 10 times the distance he traveled by bus. We're asked for the number of kilometers Joe travel by bus. We can use the Answers 'against' the prompt and TEST THE ANSWERS.

To start, we know since Joe rode the train 10 TIMES the distance he rode the bus. Thus, the distance traveled by bus is LESS than 1/11 the total distance, so that distance would have to be fairly close to 225/11 = about 20. In addition, since the TOTAL distance is exactly 225 km, it's unlikely that any of the distances traveled are non-integers, meaning that the correct answer is likely A or C.

Let's TEST ANSWERS A: 20 km
IF... Joe traveled 20 km by bus, then....
he traveled (10)(20 km) = 200 km by train.
We know he rode his bike 5 km, so...
Total Distance = 20 + 200 + 5 = 225 km

This is an exact match for what we were told, so this MUST be the answer.

Final Answer: A

GMAT assassins aren't born, they're made,
Rich