其它
Joe lives on the $3$\textsuperscript{rd}~floor. He needs to spend $12$ minutes to move from the $4$\textsuperscript{th} floor to the $5$\textsuperscript{th} floor. How many minutes does he need to climb from the $1$\textsuperscript{st} floor to the $3$\textsuperscript{rd} floor? 
Overseas Competition->Knowledge Point->Word Problem Modules->Interval Problems
$12 \times (3 - 1) = 24$ 