[原创] 10月19日 数学机井 更新至147

116. Plane P, Q tangent on the sphere S, point M on P, and N on Q. What抯 the distance of PQ?
(1) P, Q parallel
(2) Radius of the Sphere S is ?/P>

117. x=?
(1) Stem translates to x=0/0
(2) Stem tranlates to 1/0
Guess the question tests the knowledge whether 0/0 is defined or not.

118. A jar contains 10 red balls and 10 green balls. If 3 balls are removed at random without replacement, what is the probability that all 3 balls removed from the jar are green?

119. A bathroom door with a timer that sets the light reset for 15 minutes everytime someone enter or exit, ie if the door is opened by someone, the timer will turn the light on for fifteen minutes unless the door is opened again to reset it for another fifteen minutes  estimated minutes that the light is off during 8am to 10 am.
A chart is given with the time that the door is opened during the period
8:00  8:03 .........9:39 (can only remember these end time, just be familiar with the meaning, I spent a lot of time on understanding the problem)

120. how many canyons in the box?
1) envenly divided by a group of four kids, 3 leftover
2) .........................by a group of three kids, 2 leftover (not sure about the number)

121. Mary invested M dollars for interest rate n percent simple annually and Kevin invested K dollars for x percent compound semiannually  whose total interest is more in first two years
1) M >K
2) n>x

122. Pumps A, B, and C were used to fill a tank. If rate of rate of A is greater than B C is greater than rate of rate of reported here?
(1) A and B together take half the time as C
(2) B takes 3/4th of time taken by C

123. Is |x-z|>|x-y|
(1) |z|>|y|
(2) 0>x

124. If the smallest number in a set of positive integers is 3, how many numbers does the set have?9
(1) The set is average of 6
(2) Range of the set is equal to the average of the set

125. A=0.abc asked a few of the 10 is the smallest?
(1) a+b>14
(2) b+c>15

126. If a prime factor multiplied by the number of all the different product than the square root of it. it is a certain number (for a definition I have forgotten), and then asked, what is below the minimum possible number.
reference Ans: 96

127. In warehouse there are some boxes divided in stacks, each has 12.After adding 60 more, each has 14.How many boxes before adding?
1)boxes<110 before adding
2)boxes<120 after adding

128. Is the standard deviation of a certain set greater than 15,000?
1). The range of the set is 25,000
2). The mean of the set is 150,000

129. A line抯 slope is between 5-10, and point (2,3) is on the line. Which points can the line pass through?
A(4, 6)   B(4, 10)  C(4, 46)

130. A is ahead of B by 10m, at different constant speed in the same direction. Something about whho is over he speed limit.
(1) B抯 speed is 10m/h faster than the speed limit and A抯 is 10m/h slower than the speed limit
(2) B抯 speed is ?/P>

131. x > 1? 
(1) (x+1)( |x|-1) > 0
(2) |x| > 5

132. If (1/root3)^k <1/81, where k is an integer, k=?

1). k is the odd number smaller than 12

2). k is the prime number smaller than 12

Ref Ans= B

But Answer is E if there is -ve sign before K.

133. [(20-1+30-1)/2]-1 ?

134. (2)^-2/(1/2)^-3

(Ans. 1/32)

135. What is the value of 3/5 of 1/2 of 7

(Ans. 2.1)

136. A person earns $ 15 for each of the first eight days, and then double the amount for the next days. How much did the person earn in 10 days?

137. In which quadrants do the roots of the equation lie, given x and y are integers: Y = (x-2)^2 -1?

138. Someone invested in a certain account at a simple interest rate. What is the interest rate?

1). First year, he earned an interest of $3.8 from each $100 he invested.

2). First year, he earned an interest of $1.9 from each $50 he invested.

139. Is X^2+Y odd?

1). Y=3X+5

2). Y=4X-1

140. As the figure shows, ABCD is a square and triangles DEC, DFA are equilateral. What is the measure of angle EGC?

141. A set contains 21 numbers, including n. If n is 4 times the average of other 20 numbers, n is what fraction of the sum of 21 numbers?

142. If the average of 7 numbers is 5, what is the median?

1). One of the numbers is 5

2). The smallest number is 5

143. When x divided by 5, the remainder is 2; when y is divided by 5, the remainder is 3. What is the remainder when xy is divided by 5?

144. A box contains some red balls and blue balls. Is the number of the red balls 4 times the number of blue balls?

1). The probability of getting a red ball at random is 0.8

2). There are 40 balls in the box.

145. If f and g are factors of m, which of the following must be true?

I. m/(f+g) is an integer

II. m/fg is an integer.

III. m/(f-g) is an integer

146. Of the 16 numbers in a set, each is either multiple of 5, or even, or both. If 8 numbers are multiple of 5, 12 numbers are even, how many numbers are divisible by 10?

147. If you enter ABCDEFG, DABCGEF will be out put; then DABCGEF, CDABFGE will be output?After at least how many enters, ABCDEFG will appear again?

Answer:

ABCD will appear after every 4 enters, EFG will appear after every 3 enters.

The least common multiple of 3 and 4 is 12, therefore, at least 12 enters are required.

主要是翻译自CD的数学JJ

sofa.....

谢谢！！厉害！

116. Plane P, Q tangent on the sphere S, point M on P, and N on Q. What抯 the distance of PQ?
(1) P, Q parallel
(2) Radius of the Sphere S is ?/P>

E

117. x=?
(1) Stem translates to x=0/0
(2) Stem tranlates to 1/0
Guess the question tests the knowledge whether 0/0 is defined or not.

不懂！

118. A jar contains 10 red balls and 10 green balls. If 3 balls are removed at random without replacement, what is the probability that all 3 balls removed from the jar are green?

2/19

119. A bathroom door with a timer that sets the light reset for 15 minutes everytime someone enter or exit, ie if the door is opened by someone, the timer will turn the light on for fifteen minutes unless the door is opened again to reset it for another fifteen minutes  estimated minutes that the light is off during 8am to 10 am.
A chart is given with the time that the door is opened during the period
8:00  8:03 .........9:39 (can only remember these end time, just be familiar with the meaning, I spent a lot of time on understanding the problem)

25 minutes

120. how many canyons in the box?
1) envenly divided by a group of four kids, 3 leftover
2) .........................by a group of three kids, 2 leftover (not sure about the number)

E

121. Mary invested M dollars for interest rate n percent simple annually and Kevin invested K dollars for x percent compound semiannually  whose total interest is more in first two years
1) M >K
2) n>x

E

122. Pumps A, B, and C were used to fill a tank. If rate of rate of A is greater than B C is greater than rate of rate of reported here?
(1) A and B together take half the time as C
(2) B takes 3/4th of time taken by C

D

123. Is |x-z|>|x-y|
(1) |z|>|y|
(2) 0>x

E

124. If the smallest number in a set of positive integers is 3, how many numbers does the set have?9
(1) The set is average of 6
(2) Range of the set is equal to the average of the set

E

125. A=0.abc asked a few of the 10 is the smallest?
(1) a+b>14
(2) b+c>15

D

126. If a prime factor multiplied by the number of all the different product than the square root of it. it is a certain number (for a definition I have forgotten), and then asked, what is below the minimum possible number.
reference Ans: 96

96

127. In warehouse there are some boxes divided in stacks, each has 12.After adding 60 more, each has 14.How many boxes before adding?
1)boxes<110 before adding
2)boxes<120 after adding

题目不对！ 可以算出 box = 360

128. Is the standard deviation of a certain set greater than 15,000?
1). The range of the set is 25,000
2). The mean of the set is 150,000

A

129. A line抯 slope is between 5-10, and point (2,3) is on the line. Which points can the line pass through?
A(4, 6)   B(4, 10)  C(4, 46)

一个都不对！

130. A is ahead of B by 10m, at different constant speed in the same direction. Something about whho is over he speed limit.
(1) B抯 speed is 10m/h faster than the speed limit and A抯 is 10m/h slower than the speed limit
(2) B抯 speed is ?/P>

A

131. x > 1? 
(1) (x+1)( |x|-1) > 0
(2) |x| > 5
A

132. If (1/root3)^k <1/81, where k is an integer, k=?

1). k is the odd number smaller than 12

2). k is the prime number smaller than 12

B

133. [(20-1+30-1)/2]-1 ?

23

134. (2)^-2/(1/2)^-3

(Ans. 1/32)

135. What is the value of 3/5 of 1/2 of 7

(Ans. 2.1)

136. A person earns $ 15 for each of the first eight days, and then double the amount for the next days. How much did the person earn in 10 days?

15*8+2*2*15=180

137. In which quadrants do the roots of the equation lie, given x and y are integers: Y = (x-2)^2 -1?

I II IV

138. Someone invested in a certain account at a simple interest rate. What is the interest rate?

1). First year, he earned an interest of $3.8 from each $100 he invested.

2). First year, he earned an interest of $1.9 from each $50 he invested.

D

139. Is X^2+Y odd?

1). Y=3X+5

2). Y=4X-1

A

140. As the figure shows, ABCD is a square and triangles DEC, DFA are equilateral. What is the measure of angle EGC?

60

141. A set contains 21 numbers, including n. If n is 4 times the average of other 20 numbers, n is what fraction of the sum of 21 numbers?

1/6

142. If the average of 7 numbers is 5, what is the median?

1). One of the numbers is 5

2). The smallest number is 5

B

143. When x divided by 5, the remainder is 2; when y is divided by 5, the remainder is 3. What is the remainder when xy is divided by 5?

1

144. A box contains some red balls and blue balls. Is the number of the red balls 4 times the number of blue balls?

1). The probability of getting a red ball at random is 0.8

2). There are 40 balls in the box.

A

145. If f and g are factors of m, which of the following must be true?

I. m/(f+g) is an integer

II. m/fg is an integer.

III. m/(f-g) is an integer

II

146. Of the 16 numbers in a set, each is either multiple of 5, or even, or both. If 8 numbers are multiple of 5, 12 numbers are even, how many numbers are divisible by 10?

4

147. If you enter ABCDEFG, DABCGEF will be out put; then DABCGEF, CDABFGE will be output?After at least how many enters, ABCDEFG will appear again?

Answer: 12

thx

又不会了,请教NN

127. In warehouse there are some boxes divided in stacks, each has 12.After adding 60 more, each has 14.How many boxes before adding?
1)boxes<110 before adding
2)boxes<120 after adding

动作真快!

题目看都看不完  哈哈