[問題]GWD02-06(31套)

[Ricky1120]

6.The figure above shows the dimensions of a semicircular cross section of a one way tunnel. The single traffic lane is 12 feet and is equidistant from the sides of the tunnel. If vehicles must clear the yop the tunnel by at least 1/2 foot when they are inside the traffic lane, what should be the limit on the height of vehicles that are allowed to use the tunnel?

附圖基本上就是一個半圓然後標直徑12ft (原圖標20ft 我懷疑他標錯)
A.5.5ft
B.7.5ft
C.8.5ft
D.9.5ft
E.10ft

這題我的想法是12/2-0.5=5.5
不過答案是B 麻煩各位大大了