碰到的数学题，困扰数周了。！！求高人！！求解！！！！弥留之际～～～

Jolie881209

1.If an integer n is to be chosen at random from the integers 1 to 96, inclusive, what is the probability that n(n + 1)(n + 2) will be divisible by 8?
答案是5/8
2.Which of the following fractions has a decimal equivalent that is a terminating decimal?

这句话是什么意思
3.
How many seconds will it take for a car that is traveling at a constant rate of 45 miles per hour to travel a distance of 22 yards?(1 mile = 1,160 yards)答案是11【我觉得答案有问题】
4.
A total of $60,000 was invested for one year.But of this amount earned simple annual interest at the rate of x percent per year, and the rest earned simple annual interest at the rate of y percent per year.If the total interest earned by the $60,000 for that year was $4,080, what is the value of x?
(1)x = (3/4) y
(2)The ratio of the amount that earned interest at the rate of x percent per year to the amount that earned interest at the rate of y percent per year was 3 to 2.
答案是c
5.
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?
答案是60%
6.
What is the median number of employees assigned per project for the projects at Company Z?
(1)25 percent of the projects at Company Z have 4 or more employees assigned to each project.
(2) 35 percent of the projects at Company Z have 2 or fewer employees assigned to each project.
答案是c
7.
If the symbol ▼ represents either addition, subtraction, multiplication, or division, what is the value of 6 ▼ 2?【题目看不懂】
(1)10 ▼ 5 = 2
(2)4 ▼ 2 = 2
      答案a
8.Company S produces two kinds of stereos:basic and deluxe.Of the stereos produced by Company S last month,

2/3were basic and the rest were deluxe.If it takes  7/5as many hours to produce a deluxe stereo as it does to produce a basic stereo, then the number of hours it took to produce the deluxe stereos last month was what fraction of the total number of hours it took to produce all the stereos?
答案是7/17

求高人指点迷津！！！！正处于弥留中。。。。。。。。。。。

sdcar2010

A decimal that ends is a terminating decimal. In other words, a terminating decimal doesn’t keep going.

For example:
1/4 = 0.25 is a terminating decimal.

1/3 = 0.33333333... is NOT a terminating decimal.

Jolie881209

ok~~dongle ~~!!

sdcar2010

1.If an integer n is to be chosen at random from the integers 1 to 96, inclusive, what is the probability that n(n + 1)(n + 2) will be divisible by 8?

You only need to figure out when n is chosen from 1 to 8, how many groups are possible to be devided by 8 since 9 to 16 will follow a smilar pattern.

sdcar2010

How many seconds will it take for a car that is traveling at a constant rate of 45 miles per hour to travel a distance of 22 yards?(1 mile = 1,160 yards)答案是11

1 mile = 1760 yards

sdcar2010

5.
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?

If 60 percent of the passengers with round-trip tickets did not take their cars abroad the ship, then 40% of the passengers with round-trip tickets DID take their cars abroad the ship.  So 20% is only 40% of the total for passengers held round-trip tickets.

The answer should be 50%

sdcar2010

If the symbol ▼ represents either addition, subtraction, multiplication, or division, what is the value of 6 ▼ 2?【题目看不懂】
(1)10 ▼ 5 = 2
(2)4 ▼ 2 = 2
     答案a

(1) ▼ could ONLY be devision
(2) ▼ could be either devision or subtraction

sdcar2010

8.Company S produces two kinds of stereos:basic and deluxe.Of the stereos produced by Company S last month,
2/3were basic and the rest were deluxe.If it takes  7/5as many hours to produce a deluxe stereo as it does to produce a basic stereo, then the number of hours it took to produce the deluxe stereos last month was what fraction of the total number of hours it took to produce all the stereos?
答案是7/17

Categories  Basic  Deluxe
number        2         1
unit time       1        7/5
total time      2        7/5

So the total time for both = 17/5.

Desired ration = total time for Deluxe/ total time for both = (7/5)/(17/5)=7/17

sdcar2010

6.
What is the median number of employees assigned per project for the projects at Company Z?
(1)25 percent of the projects at Company Z have 4 or more employees assigned to each project.
(2) 35 percent of the projects at Company Z have 2 or fewer employees assigned to each project.
答案是c

Based on both (1) and (2), there are 40% projects at Company Z have 3 employees assigned to each project.  The median has to be 3, counting from either ends.

Jolie881209

牛人！！