?$(\frac {1}{2}-\frac {1}{4})\div (12 - 10)=\frac {1}{8}$?
?$ 10+(1 - \frac {1}{4})\div \frac {1}{8} = 16($?分鐘?$)$?
?$ \frac {1}{4}\div 10=\frac {1}{40}$?
?$ 1\div \frac {1}{40}=40($?分鐘?$)$?
?$ 40 - 16 = 24($?分鐘?$)$?
答:他到達(dá)考場所花的時(shí)間比一直步行到達(dá)考
場要提前?$24$?分鐘。