我又来问数学题了！！！求各位NN解答顺便为备考的各位积攒RP！！！

dt815

Q6:












The figure above shows the dimensions of a semicircular cross section of a one-way tunnel.  The single traffic lane is 12 feet wide and is equidistant from the sides of the tunnel.  If vehicles must clear the top of the tunnel by at least ½ 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?

A.    5½ ft
B.    7½ ft
C.    8 ½ ft
D.    9½ ft
E.    10 ft

dt815

为什么上不了图。。。。就是GWD数学2里的第六题啊。。。没图大家也能自动联想么。。。

dt815

Q18:
On a certain transatlantic crossing, 20 percent of a ship’s passengers held round-trip tickets and also took their cars abroad the ship.  If 60 percent of the passengers with round-trip tickets did not take their cars abroad the ship, what percent of the ship’s passengers held round-trip tickets?

A.    33 1/3%
B.    40%
C.    50%
D.    60%
E.    66 2/3%


还有这道。。。

dt815

以及这道。。。

Q29:
If 1050 – 74 is written as an integer in base 10 notation, what is the sum of the digits in that integer?

A.   424
B.   433    
C.    440
D.    449
E.    467

蜜柚茶叶蛋

Q29: 10的50次方减74，问所得整数的各个位数相加之和。
1000-74=926 此为所得整数的后三位，前47位数均为9。因此，所得整数各个位数相加之和为：9*47+9+2+6=440。

如有错误请指正。

kimsung312

童鞋：The figure above shows the dimensions of a semicircular cross section of a one-way tunnel.  The single traffic lane is 12 feet wide and is equidistant from the sides of the tunnel.  If vehicles must clear the top of the tunnel by at least ½ 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?

A.    5½ ft
B.    7½ ft
C.    8 ½ ft
D.    9½ ft
E.    10 ft

这道题选B

思路是用执教三角形的3遍关系 A2+B2=C2
因为它是半圆所以圆心到高度那个距离就是半径10ft， 12ft的车道开在半圆的正中间，两边就会各留出4ft的距离。从而得出高和低相交的点到圆心的距离是8ft。根据思路里面的公式：10的平方-8平方=64， 高就是8ft，题中要求要预留1/2ft的距离，所以8-0.5=7.5 选B

希望解释得清楚哈

kimsung312

Q29: 10的50次方减74，问所得整数的各个位数相加之和。
1000-74=926 此为所得整数的后三位，前47位数均为9。因此，所得整数各个位数相加之和为：9*47+9+2+6=440。

如有错误请指正。

-- by 会员 蜜柚茶叶蛋 (2012/5/4 9:11:45)

这个答案是完全正确地 ：）

dt815

没有错。。。谢谢你哈
我发现我好像是题理解错了

dt815

我想说这个题我还是没看懂啊。。。