几道简单的GRE数学题

题目

几道简单的GRE数学题
1 two successive discounts of 20 percent and 40 percent are equivalent to a single discount of x percent.
x 52
2 the number of ¼-inch lengths in a 4-inch length 1
3 the number of inches in the perimeter the number of square inches in the area of a square region
of a square region with side of s inches with side of s inches
4 A total of $480 is in a certain cash register. All of the money is in one-dollar and five-dallar bills, and there are 30 more one-dollar bills than five-dollar bills.
the sum of 30 and the number of 105
five-dollar bills in the cash register.
5 the number of the longest between the number of integers between 6 and 126
15 and 51 that are squares of integers. that are cubes of integers.
6 the maximum number of solid cubes having 4
edges of length ½ meter that can be placed
inside a cubical box having inside edges of length
1 meter.
7 Ms.Smith got an 8 percent cost-of-living raise of $20 per week,
Ms.Smith's new weekly salary $260

答案

先说第一题吧,说的是二成的折扣上再来四成的折扣等于.
也就是说0.8*0.6=0.48,也就是说x是百分之52的折扣
二题,在4英尺长中有几个四分之一英尺长,就是4除以0.25=16
三题不对吧?
四题,就是说有一堆一元和一堆五元的加起来是480,一元比五元多30张,列个方程.x是一元的,y是五元的：x+5y=480 x-y=30 解一下就出来了
五题,比较6到126之间的立方的整数的个数和5到51之间平方的整数的个数.立方的分别是8,27,64,125一共四个；平方的是9,16,25,36,49一共五个,所以平方个数多
六题,说一个边长是0.5米的立方体在边长是1米的立方体里最多能放几个.1除以0.5=2 2的三次方=8个
七题,就是说每个月的开销涨了20,是原来的百分之八,所以原来每月的开销就是：20除以百分之八等于250,然后再加上涨的20就是270,比260大
这么多字打得幸苦,楼主赏赏分吧