So she earns $60 per day working, but only saves $50. To solve this equation you have to multiply $50 to each day she works. If the total has to be exactly $2,000 then you must multiply 50 x 36.4 and that equals $2,000. Your answer should be 36.4 days.
I think that the altimeter would read as '0'. Positive readings would show that she was above sea level and negative readings we would show that she was below sea level. I hope that this helps