official quant thread for cat08

[vaibhav2cool]

Originally Posted by linksuresh

ans = c) x<41
very true

what is the logic behind it?

[vaibhav2cool]

b) Miss Cohen is in her prime, Today is her birthday and her age( as it was last year) product of two primes P1 and P2, where P1-P2=P3.P4, where P3 and P4 are primes. P3-P4=P5 where P5 is also a prime. Given that she is not yet 100 years old. Then
a) She can have 4 ages
b) She can have 2 ages
c) given that all primes are distinct she can have only one age
d) a and c
e) b and c

Read this question carefully!! its a famous problem, and unless you read it well, there is no way you can get it right !!

P.S Try to do it logically, without just doing option maths!![/quote]



p1 p2 p3 p4 p5 s.no
37 2 7 5 2 1
17 2 5 3 2 2
29 3 13 2 11 3
17 3 7 2 5 4
13 3 5 2 3 5
19 5 7 2 5 6


option c,d,e can be ruled out because s.no 3 and s.no 5 clearly show two different ages wen all primes are distinct.


now her age previous year also had the same characterstic.
now this criteria none of the above cases satisfy...
dnt knw...i think m goin wrong smwhere

[getintoiimb]

puys pls solve me with these qns with the steps

1)the price of sugar is reduced by 25% but inspite of the decrease aayush ends up increasing his expenditure on sugar by 20%.what is teh % change in his monthly consumption of sugar

ans : +60%

2)an ore contains 25% of an alloy that has 905 iron.other than this i the remaining 75% of the pre there is no iron.how many kgs of the ore are needed to obtian 60 kg of pure iron?

ans :266.66 kg

3)the ratio of jim's salary for october to his salary for november is 1.5:1.333 and the ratio of the salary for nov to dec was 2:2.6666.the worker got 40 Rs more for dec than for oct and received a bonus 40 % of the salary for 3 months.fond the bonus.(assume that the number of workdaysis the same in every month)

ans : 222.22 Rs

4)A is 50% more than B,C is 2/3 of A and D is 60% more than C.now each of A,B,C and D is increased by 10%.find what % of B is D(after the increase)

ans :160%

5)in a village consisting of p persons,x% can read and write.of the males alone y% and of the females alone z% can read and write.find the number of males in the village in terms of p,x,y and z if z<y

ans : (p(x-z))/(y-z)

6)a fraction is suck that if the double of the numerator and the triple of the denominator is changed by +10% and -30% respectively then we get 11% of 16/21.find the fraction

ans : 2/25

7)800 ppl were supposed to vote on a resolution byt 1/3rd of the people who had decided to vote for the motion were abducted.however the opponents through some emans managed to increase their strength by 100%.the motion was then rejected by a majority which was 50% of that by which it would have been passed if none of these changes would have occured.how many people finally voted for the moition and against the motion?

ans : 200(for),400(against)

of the adult population in nagpur 45 % of men adn 25 % of women are married.what % of the total population of adults is married(assume that no man marries more than one woman and vice versa)

ans : 32.14%

Thanks !

[getintoiimb]

puys pls solve these qns for me with the steps

1)the price of sugar is reduced by 25% but inspite of the decrease aayush ends up increasing his expenditure on sugar by 20%.what is teh % change in his monthly consumption of sugar

ans : +60%

2)an ore contains 25% of an alloy that has 905 iron.other than this i the remaining 75% of the pre there is no iron.how many kgs of the ore are needed to obtian 60 kg of pure iron?

ans :266.66 kg

3)the ratio of jim's salary for october to his salary for november is 1.5:1.333 and the ratio of the salary for nov to dec was 2:2.6666.the worker got 40 Rs more for dec than for oct and received a bonus 40 % of the salary for 3 months.fond the bonus.(assume that the number of workdaysis the same in every month)

ans : 222.22 Rs

4)A is 50% more than B,C is 2/3 of A and D is 60% more than C.now each of A,B,C and D is increased by 10%.find what % of B is D(after the increase)

ans :160%

5)in a village consisting of p persons,x% can read and write.of the males alone y% and of the females alone z% can read and write.find the number of males in the village in terms of p,x,y and z if z<y

ans : (p(x-z))/(y-z)

6)a fraction is suck that if the double of the numerator and the triple of the denominator is changed by +10% and -30% respectively then we get 11% of 16/21.find the fraction

ans : 2/25


7)800 ppl were supposed to vote on a resolution byt 1/3rd of the people who had decided to vote for the motion were abducted.however the opponents through some emans managed to increase their strength by 100%.the motion was then rejected by a majority which was 50% of that by which it would have been passed if none of these changes would have occured.how many people finally voted for the moition and against the motion?

ans : 200(for),400(against)

8 )of the adult population in nagpur 45 % of men adn 25 % of women are married.what % of the total population of adults is married(assume that no man marries more than one woman and vice versa)

ans : 32.14%

Thanks !

[utsavmamoria]

4)A is 50% more than B,C is 2/3 of A and D is 60% more than C.now each of A,B,C and D is increased by 10%.find what % of B is D(after the increase)

ans :160%

Putting the words in Equations

A = 3/2 B

C = 2/3 A

D = 8/5 C

Putting everything in terms of B

A = 3/2 B

C = B

D = 8/5 B

If all of A, B , C and D are increased by 10% , It should not effect the %tages as they will get cancelled out.

So , D is 8/5 or 160% of B

6)a fraction is suck that if the double of the numerator and the triple of the denominator is changed by +10% and -30% respectively then we get 11% of 16/21.find the fraction

ans : 2/25

Let the fraction be x/y

So the increased Fraction 2x/3y

Applying the % changes, we get

2.2x/2.1y

According to the given condition

2.2x/2.1y = 11/100 x 16/21

Soving we get

x/y = 2/25

[shagils]

Originally Posted by yudhajeet

"Dravid and Sachin each had a certain number of playing marbles. Dravid lost a game to Sachin and had to give Sachin half of his marbles. In the second game, Sachin lost and had to give three-fourths of his marbles to Dravid, who now had thirty marbles. Finally, the two played a third game. Sachin won and acquired some of Dravid?s marbles.At this point, each boy had exactly the number of marbles he had started with, and Dravid had twice as many marbles as Sachin. How many marbles did Sachin has in the beginning?"

Give 24 hrs before posting your answrs to this q..

sachin had 12 marbles in the beginning

[ankaj]

Originally Posted by getintoiimb

puys pls solve these qns for me with the steps

1)the price of sugar is reduced by 25% but inspite of the decrease aayush ends up increasing his expenditure on sugar by 20%.what is teh % change in his monthly consumption of sugar

ans : +60%
Sol:
As the price of sugar decreases by 25% u would get same amount for 75%, say earlier 1 Kg was for 100Rs
NOw 1 kg is for Rs 75
Total amount spent on sugar= 100+20
extra amount spent=45
extra quanity is bought for this Rs 45 @ rate of 75, so 3/5=60%

2)an ore contains 25% of an alloy that has 905 iron.other than this i the remaining 75% of the pre there is no iron.how many kgs of the ore are needed to obtian 60 kg of pure iron?

ans :266.66 kg

3)the ratio of jim's salary for october to his salary for november is 1.5:1.333 and the ratio of the salary for nov to dec was 2:2.6666.the worker got 40 Rs more for dec than for oct and received a bonus 40 % of the salary for 3 months.fond the bonus.(assume that the number of workdaysis the same in every month)
O : N
1.5 : 4/3
O/N= 9/8

N/D= 3/4

O:N=27:24:32
LEt sal of Oct = x
27/32=x/ (x+40+.4*3X)

ans : 222.22 Rs

4)A is 50% more than B,C is 2/3 of A and D is 60% more than C.now each of A,B,C and D is increased by 10%.find what % of B is D(after the increase)

ans :160%
As all are in respective ratios and they are increased uniformaly there s no change in ratio

5)in a village consisting of p persons,x% can read and write.of the males alone y% and of the females alone z% can read and write.find the number of males in the village in terms of p,x,y and z if z<y

ans : (p(x-z))/(y-z)

Men= M
women= P-m
XP= ym+ Zp -Zm
m= P(X-Z)/(y-Z)

6)a fraction is suck that if the double of the numerator and the triple of the denominator is changed by +10% and -30% respectively then we get 11% of 16/21.find the fraction

ans : 2/25


7)800 ppl were supposed to vote on a resolution byt 1/3rd of the people who had decided to vote for the motion were abducted.however the opponents through some emans managed to increase their strength by 100%.the motion was then rejected by a majority which was 50% of that by which it would have been passed if none of these changes would have occured.how many people finally voted for the moition and against the motion?

ans : 200(for),400(against)

8 )of the adult population in nagpur 45 % of men adn 25 % of women are married.what % of the total population of adults is married(assume that no man marries more than one woman and vice versa)

ans : 32.14%

Thanks !

Answers within the questions

[jigar_er_civil]

Originally Posted by getintoiimb

puys pls solve these qns for me with the steps

1)the price of sugar is reduced by 25% but inspite of the decrease aayush ends up increasing his expenditure on sugar by 20%.what is teh % change in his monthly consumption of sugar

ans : +60%

2)an ore contains 25% of an alloy that has 905 iron.other than this i the remaining 75% of the pre there is no iron.how many kgs of the ore are needed to obtian 60 kg of pure iron?

ans :266.66 kg

3)the ratio of jim's salary for october to his salary for november is 1.5:1.333 and the ratio of the salary for nov to dec was 2:2.6666.the worker got 40 Rs more for dec than for oct and received a bonus 40 % of the salary for 3 months.fond the bonus.(assume that the number of workdaysis the same in every month)

ans : 222.22 Rs

4)A is 50% more than B,C is 2/3 of A and D is 60% more than C.now each of A,B,C and D is increased by 10%.find what % of B is D(after the increase)

ans :160%

5)in a village consisting of p persons,x% can read and write.of the males alone y% and of the females alone z% can read and write.find the number of males in the village in terms of p,x,y and z if z<y

ans : (p(x-z))/(y-z)

6)a fraction is suck that if the double of the numerator and the triple of the denominator is changed by +10% and -30% respectively then we get 11% of 16/21.find the fraction

ans : 2/25


7)800 ppl were supposed to vote on a resolution byt 1/3rd of the people who had decided to vote for the motion were abducted.however the opponents through some emans managed to increase their strength by 100%.the motion was then rejected by a majority which was 50% of that by which it would have been passed if none of these changes would have occured.how many people finally voted for the moition and against the motion?

ans : 200(for),400(against)

8 )of the adult population in nagpur 45 % of men adn 25 % of women are married.what % of the total population of adults is married(assume that no man marries more than one woman and vice versa)

ans : 32.14%

Thanks !

1st ans

if price is 1 rs/kg and 100 rs total expenditure

now price is 0.75 ans total exp.120 so total sugar=160kg

so 60% more suger buy


4)A is 50% more than B,C is 2/3 of A and D is 60% more than C.now each of A,B,C and D is increased by 10%.find what % of B is D(after the increase)

here B=x,A=1.5x,C=0.67*1.5x,D=1.6*0.67*1.5x

so D/B=1.6=160%






Little Star

[implex]

Originally Posted by implex

b) Miss Cohen is in her prime, Today is her birthday and her age( as it was last year) product of two primes P1 and P2, where P1-P2=P3.P4, where P3 and P4 are primes. P3-P4=P5 where P5 is also a prime. Given that she is not yet 100 years old. Then
a) She can have 4 ages
b) She can have 2 ages
c) given that all primes are distinct she can have only one age
d) a and c
e) b and c

Read this question carefully!! its a famous problem, and unless you read it well, there is no way you can get it right !!

P.S Try to do it logically, without just doing option maths!!

initial set
p1 p2 p3 p4 p5 age
13 3 5 2 3 39
17 2 5 3 2 34
17 3 7 2 5 51
19 5 7 2 5 95
29 3 13 2 11 87
37 2 7 5 2 74

now look at this
her age( as it was last year) product of two primes P1 and P2
but 50 and 73 are not product of primes, ruled out!!

now again "Miss Cohen is in her prime" this rules out 39 and 34

if all primes are distinct we get 87, if not 87 and 95

so option e)!!!!

[parmindersaluja]

NEW QUESTION
Minimum and maximum values of the function:
f(x) = |2x-3| + |x+2| - |4-3x|
a) -3<= f(x)<=8/3
b) 0<= f(x)<=3
c) -3<= f(x)<=6
d) -3<= f(x)<=11/3