Answer: B
Solution:
=（（10-9）+（8-7）+（6-5）+(4-3)+(2-1)）/(1+(-2+3)+(-4+5)+(-6+7)+(-8+9))=5/5=1.
Answer: D
Solution:
The fraction in question is equal to 1.25. Expressing all of the choices we have,
A: 1.25; B: 1.25; C: 1.25; D: 1.2; E: 1.25; It's clear then that choice D is the answer.
Answer: D
Solution:
To maximize anything of the form a-b,, we maximize a and minimize b. The maximal element of the set is 12 and the minimal element is -16, so the maximal difference is 12--16=28.
Answer: E
Solution:
From the information given, 25-1-1-5=28 hits were single. Thus, the percentage was28/35=80%.
Answer: E
Solution:
The area of the shaded region is the area of the circle subtracted from the area of the rectangle. The diameter of the circle is 1, so the radius is 1/2 and the area is Pi*0.5*0.5.
The rectangle obviously has area 2*3=6, so the area of the shaded region is 6-Pi*0.5*0.5, This is closest to 5.
Answer: D
Solution:
The first triangle represents 1+3-4, The 2nd triangle represents 2+5-6. Solving the first triangle, we get 0 Solving the 2nd triangle, we get 1.Since we have to add the 2 triangles the final answer is 1.
Answer: A
Solution:
The highest digit sum for three-digit numbers is 9+9+9=27. Therefore, the only possible digit combination is 9,9,8. Of course, of the three possible numbers, only 998 works.
Answer: C
Solution:
1500*0.1=150, so the store owner is $150 below profit. Therefore he needs to sell 150+100=250 dollars worth of pencils. Selling them at $0.25 each gives 250/0.25=1000.
Answer: B
Solution:
The graph show that the ratio of men to total population is 1/3, so the total number of men is 1/3 * 480=160.
Answer: B
Solution:
Because the smaller triangles are congruent, the shaded area take 10/16 of the largest triangles area, which is 8*8/2=32, so the shaded area is 10/16 *32=20.
Answer: B
Solution:
The total frequency is 50+60+40+60+40=250, with the blue frequency of 60. Therefore, the precentage that preferred blue is 60/250=24%.
Answer: C
Solution:
In the 30,000 miles, four tires were always used at one time, so the amount of miles the five tires were used in total is 30,000*4=120,000. Five tires were used and each was used equally, so each tire was used for 120,000/5=24,000.
Answer: B
Solution:
Because there was an odd number of scores, 91 must be the middle score. 94 appears twice. Also, the sum of the five numbers is 90*5=450. Thus, the sum of the lowest two scores is 450-91-94-94=171.
Answer: D
Solution:
Four gallons is 1/2 – 1/3=1/6. Thus, capacity of the tank in gallons is 6*4=24.
Answer: C
Solution:
The sequence consists of repeated strings of 9 letters, ABCDEDCBA. When 1992 is divided by 9, the remainder is 3, and so the 1992nd letter in the sequence is the 3rd letter of the smaller string, C.
Answer: B
Solution:
The volume of a cylinder is given by the formula V=Pi*r*r*h. The given cylinder therefore has a volume of 500Pi. Plugging in the radius and height of the answer choices, we find the cylinder that has a volume of double the volume is 1000Pi. (B )
Answer: B
Solution:
By Triangle Inequality, 6.5+s>10, and therefore S>3.5. The smallest whole number that satisfies this is 4.
Answer: A
Solution:
The average speed is given by the total distance traveled divided by the total time traveled.(80+0+100)/4=45.
Answer: C
Solution:
There are 21 pairs of consecutive exits. To find the maximum number of miles of one of these, the other 20 must be equal to the minimum number yielding a total of 5*20=100 miles. The longest distance must be 118-110=18.
Answer: D
Solution:
If pattern d were to be folded into a cube, the topmost square would overlap the rightmost square.
Answer: B
Solution:
The ratio of the sales of the group with more sales and the sales of the group with less sales is largest in B which is 5/3=1.67.
Answer: C
Solution:
Add 2 sides for each new tile. So the new perimeter is 14+2+2=18.
Answer: B
Solution:
When the first dice is 1, there are no possibilities for the second dice.
When the first dice is 2, the second dice can be 6, giving one possibility.
When the first dice is 3, the second dice can be 4,5,6, giving three possibilities.
When the first dice is 4, the second dice can be 3,4,5,6, giving four possibilities.
When the first dice is 5, the second dice can be 3,4,5,6, giving four possibilities.
When the first dice is 6, the second dice can be 2,3,4,5,6, giving five possibilities.
The total number of ways for the product to greater than 10 is 1+3+4+4+5=17 and the total number of possibilities is 6*6=36, yielding a probability of 17/36.
Answer: A
Solution:
The side of the square of made up of two radii, and the area of the square is 6*6=36. The unshaded region of the square is composed of four quarter circles, and has the area of one circle, which is 9*Pi. The area of the shaded region is 36-9*Pi which is 7.2
Answer: D
Solution:
The amount left in the container as follows: After the first pour 1/2 remains, after the second 1/2*2/3 remains, etc.
This becomes the product of remaining: 1/2 * 2/3 * 3/4 *… * x/(x+1). when the remaining is 1/10, thus x=9.
中文解析：
第一次倒出后，剩余1/2，第二次倒出后，剩余1/2 * 2/3； 第三次倒出后，剩余（1/2)*（2/3) *(3/4), 第四次倒出后，剩余 （1/2）*（2/3）*（3/4）*（4/5），。。。。第n次倒出后，剩余： （1/2)*(2/3)*(3/4)*...*(n/n+1).
根据题意： （1/2）*（2/3）*（3/4）*...*(n/n+1)=1/10; 求得n=9. 答案是D。
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