please help me by solving these problems:part-2

[ahad]

1.100 < a < b < 1000
Col A: 1/a - 1/b Col B: 1/100 - 1/1000

2. A rectangle was given. Length (base) (labelled as MS) = 16, Width (labelled as SR) = 5. If a
point P is taken on the base randomly, What is the probability that length of PR is less than 13.

3. Given that the sales of store A increases from 20% to 24% and sales of store B decreases from
24% to 20%
Col A: percentage increase in sales of store A Col B: percentage decrease insales of store B

4. If (a^3)/(b^3) = -1 then
What is the value of (a^-1)+(b^-1) =

5. Given that SRT is an isosceles triangle with SR=ST. P is a point on RT, with a different
distance from both R and T. Which one of the following must be true?
i)SP < SR ii) SP > RP iii) SP < RT

6. Given a cylinder of radius 5 and height 8. Find the largest line that can be drawn joining any
two points in the cylinder?
A. 2Sqrt41 B. Sqrt81 C. Sqrt154 and so on

7. Given Principal amount as P,rate of interest as R ,and the amount increases from 1995 to 2000
and 2000 to 2005 each time by r%. so that the total amount was (7/5)P at the end of 2 yrs .

Col A : R Cola B: 20

8. Given a triangle ABC, in which a square is inscribed. If the base of the triangle is 4 times the
side of the square, then
Col A: The altitude CD (if D is the mid point of AB)
Col B: Side of the square

9. Col A: Standard Deviation of 23, 24, 25, 26, 26, 26
Col B: Standard Deviation of 25, 26, 27, 28, 29, 30

10.Given a cuboid whose faces are painted red and the cuboid is cut vertically into 27 pieces. If
the pieces are taken out after cutting vertically then how many of these 27 pieces had red color
face?

11. Col A: Standard Deviation of 4, 5, 6, 7, 8
Col B: Standard Deviation of 33, 33, 34, 34, 35, 35

12. Given that -1 > x > 0 and assume that x=!0
which of the following is true?
A. x^3 < x^2 < x
B. x^2 < x < x^3
C. x < x^2 < x^3
D. x < x^3 < x^2

13. A survey was conducted for 248 companies. In that 120 companies receive calls using a
switch and 90 companies among those have voice calls facility.
Col A: The number of companies that doesn't have voice calls facility but have switch facility.
Col B: 62.

14. Given an series s1, s2, s3,.............sn and Sn+1=(1/2)Sn and s1=1/2.
Col A: s6
Col B: 2^15(s21)

15. When a square with a center c is rotated through an angle 45 degrees, it has a new centre c'. If
the length of the square side was given as 5, Find the distance between c and c'?

16. Find the percentage of numbers between 100 & 299 inclusive which end with
3,4,5,6,7,8,9,(2+3^1/2)(2-3^1/2). (I did not understand it)

17. There are 28 men in a room in that 14 men are selected out of which 7 are under 50 years.
Col A: Percentage of men under 50
Col B: 40%

[chestnut.cc]

1. You already asked the first sum?

2.ImageShack - Hosting :: ppwn2.jpg

the probability of the line being less than 13 will be the area of the triangle/ area of the rectangle... itll actually be inclusive of 13 so look for the answer that comes closest but is less than that ans... ie 1/2*12*5/5*16 = 3/8

3. C or A... 4% absolute increment... or 4% and -4%...

4. a = -1/b... 1/a + 1/b = -b +1/b = -b^2+1/b = 1-b^2/b

5. i

6. 2root41

7. The timespan is shown as 10yrs... if its 2 yrs... Let P= 500... therefore amount = 700... interest = 200 = PRT = 500*R*2... R = 20%... C

8. D

9. B

10. 2

11. A

12. Makes no sense at all

13. B

14. C... (nth term of a GP)

15. 2.5

16. I don't sup anyone did...

17. D... the only thing you can say is that at least 25% of the men are under 50 yrs...

[Oink]

Ive only given answers to the questions which cheshnut dint answer
1) B
( Consider A - B , if Value of A is reduced and value of B is increased, the difference reduces. It is what is being done in the question, anything after 1/100 means reducing value ( denominator is increased ) and anything before 1/1000 means increasing value ( denominator is reduced ) )
12 ) D
16) i agree with cheshnut .. makes no sense at all


PS : @ cheshnut , in the 2nd question, why is probability calculated by the area ?? i mean, if PR = 13, then PS = 12, so MP = 4 , so shouldnt we calculate the probability by the lengths rather than area ? i.e. 12/16 or 3/4 ?
regards

[chestnut.cc]

The reason being that the division of the line can be as small as we want it to go... the area of the triangle represents the sample space of all the points which satisfy the condition (PS<12, PR<13)... however small we choose to go... and the area of the rectangle represents the entire sample space... ie we can come as close to 13 as we want and still find more lengths satisfying the condition... 12.9... 12.99... 12.99999... you get the picture... so the probability will be something v close to 3/8... PR=13 is the boundary condition when PR =12... we want everything below that point... however i could be wrong... :s

[ahad]

please explain answers for 10 and 15.i did not understand them.

[chestnut.cc]

10. I'm guessing here since im not sure if I understood the question... if the cuboid is cut vertically into 27 pieces and if the broad side of each piece is considered its face... then there will be only 2 blocks with red faces... namely those chopped off at either end...

15. Sorry... my bad... i made a mistake in that one...


ImageShack - Hosting :: sumbu3.jpg


refer diagram... consider the square lying on the x and y axes... then rotate it... then the distance betn the centers can be found by finding the coordinates of the new center... since the new center will lie on the y axis... the x co ordinate is 0... the y coordinate lies at the center of the new square... ie at the bisection of the diagonals... which are 5root2 each... hence the y coordinate is 5/root2... therefore by distance formula...

cc' = root[ (0-2.5)^2 + {(5/root2) - 2.5}^2]

Onerous calculations... so i could be wrong... :s

[greatgre]

16. Find the percentage of numbers between 100 & 299 inclusive which end with
3,4,5,6,7,8,9,(2+3^1/2)(2-3^1/2). (I did not understand it)

Ans:: 81%

There are totally 200 nos between 100 and 299.
Now the ques asks for the percentage of nos in this 200 , that end with 3,4,5,6,7,8,9,1(simplify the last expression)
To find this percentage find out the number of nos that do no end with the given specification
this no comes to around 38.
Hence the nos that end with the given specification comes to 162 .
162 is now what percent of 200??? It is 81 %

Hence the ans is 81%.

[e.cartman]

Chestnut, can you please explain how the answer to this question 8 is D?
"Given a triangle ABC, in which a square is inscribed. If the base of the triangle is 4 times the
side of the square, then
Col A: The altitude CD (if D is the mid point of AB)
Col B: Side of the square"

Vertex C on top. Base AB. Altitude AD seems > side always. No?

[Jeanette]

Originally Posted by greatgre

16. Find the percentage of numbers between 100 & 299 inclusive which end with
3,4,5,6,7,8,9,(2+3^1/2)(2-3^1/2). (I did not understand it)

Ans:: 81%

There are totally 200 nos between 100 and 299.
Now the ques asks for the percentage of nos in this 200 , that end with 3,4,5,6,7,8,9,1(simplify the last expression)
To find this percentage find out the number of nos that do no end with the given specification
this no comes to around 38.
Hence the nos that end with the given specification comes to 162 .
162 is now what percent of 200??? It is 81 %

Hence the ans is 81%.

Can you explain how there are 38 numbers between 100-299 inclusive that end in 0 or 2?

[chestnut.cc]

the thing is i cant figure out how a square can be inscribed in a triangle...so i marked D... but if you assume one of its sides is part of one of the triangles sides and it has a point in common with the other two sides... then yes i think the altitude will always be larger than either the side or the diagonal... and in the latter case being larger than the diagonal means its larger than the side...

There will be 2 nos that end with 0 or 2 in every ten nos... that comes to 40 betn 100 and 299... :s