智能学辅导考试QQ交流群：298985181    

　　智能学辅导中小学QQ交流群：99107564     欢迎关注中小课外辅导官方微博 

1. A football team has won 10 games and lost 5 games. If the team wins the remaining games of the season, it will have won 80 percent of its games. How many games in total will have been played?

2. The amount of time taken to paint a wall is inversely proportional to the number of painters working on the job. If it takes 3 painters 5 days to complete such a job, how many days longer will it take if there are only 2 painters working?

3. Line l and line m lie in the same plane but have no points in common. They are both tangent to a circle of area 9π. What is the shortest distance between any point on l and any point on m?

4. A box contains 5 chocolates with soft centers, 6 with nut centers, and 11 with hard caramel centers. Three students take turns to take a chocolate at random from the box and eat it. If the probability that all three students take soft centers is 1/x, what is the value of x?

5. At one point in a game the shooting team has a ratio of hits to misses of 5:1. After the next team misses the nest three shots, which are the last in the game, its ratio of hits to misses is 5:2. What is the total number of shots taken by the team in the game?

Explanation:

1. Correct Answer: 25

Explanation:

Let the total number of games to be played = n

Number lost = 5; number won = n-5

n-5 = 80/100 x n; n - 5 = 0.8n; 0.2n = 5; n = 25

2. Correct Answer: 2.5

Explanation:

For inverse proportions remember the formula x1y1 = x2y2

Here initial painters x days = final painters x days; 3 x 5 = 2 x days

Total days taken will be 15/2 = 7.5, but there is a catch: you were asked how much longer it would take. Initial time was 5 days so it will take 2.5 days longer.

3. Correct Answer: 6

Explanation:

The description tells us that l and m are parallel lines with the circle lying between and touching both. Area of the circle = πr2 = 9 π. Radius = 3 and diameter = 6.

4. Correct Answer: 154

Explanation:

The total number of chocolates to start with is 22. The first student has a chance of 5/22 of taking a soft center. The second student has a only 21 sweets left of which 4 could be soft: his chance is therefore 4/21. Similarly the third student has a chance of 3/20

Total probability is obtained by multiplying all these chances together: (5/22)(4/21)(3/20) = 1/154 [It is best to cancel the terms down rather than using a calculator because we want a fraction not a decimal]

5. Correct Answer: 21

Explanation:

A ratio of 5: 2 means 5x: 2x. Total shots = 7x. The last three shots added one unit to the ratio, and so x = 3. 7x = 21

延伸阅读：

SAT数学考试出题上有何特点？

SAT数学图表题应试技巧

SAT数学常用公式

更多阅读资料：
/guide/category/40/.html