Austin and Jake start descending from the 9th floor of a building at the same time. Austin uses the elevator and Jake uses the stairs, descending 3 steps every second. The stairs have 30 steps across each floor. If the elevator will take a minute to get to ground level, how many seconds later will Jake get to the ground floor?
Jake has to descend 30 steps on 9 floors for a total of 9*30 = 
<gadget id="calculator">30*9</gadget>
<output>270</output>
270 steps.
He descends 3 steps every second so he will descend 270 steps in 270/3 = 
<gadget id="calculator">270/3</gadget>
<output>90</output>
90 seconds.
Austin will get down after only a minute (60 seconds) so Jake will get down 90-60 = 
<gadget id="calculator">90-60</gadget>
<output>30</output>
30 seconds later.

<result>30</result>