其它
Judy needed to reach the $10$\textsuperscript{th} floor of a building. It took her $40$ seconds to walk from the $1$\textsuperscript{st} floor to the $5$\textsuperscript{th} floor. How many seconds will it take to go from the $3$\textsuperscript{rd}~to the $10$\textsuperscript{th} floor at the same speed? 
Overseas Competition->Knowledge Point->Word Problem Modules->Interval Problems
$40 \div (5 - 1) = 10$  $(10 - 3) \times 10 = 70$ 