Smart way to earn $$

Source:F math lecturer
A computer expert was sitting beside an engineer inside a plane ...
As usual ,the computer expert will take out his lap-top and play around with it,it was no surprice to the engineer ..10 hours later..the engineer was soo surprise to see the computer expert still playing with his lap -top!!!Due to his curiousity,he asked"What r u doin with your lap-top?"The computer expert then proudly say that he is a computer expert and he also said that he could get any information in the world is in his lap-top!!
The computer engineer then challenged the engineer to ask him any questions....he will answer them with his lap-top...if he couldnt answer them he will give the engineer $5 but if the engineer couldnt answer the question the computer engineer ask.... then the engineer will pay him $3...The engineer agreed..The engineer asked him"What animal climbs a mountain with 4 legs then comes down with 3 legs??"So the computer expert then check it with his lap-top...surprisingly...he cant find the answer...so he gave $5 to the engineer...Later..the computer expert then ask the engineer the same question..the engineer didnt answer him and just give him $3.......