[hanuman]

Originally Posted by harmeetSekhon

if have prob plz reply ASAP


Using the numbers 3, 3, 8, 8 (in any order), make a mathematical expression that equals 24. You can use only addition, subtraction, multiplication, and division (and parentheses), but in any order you wish. Note that you have to use all four numbers; otherwise 3 times 8 would be valid -- which is not correct according to condition.

Sorry guys,made a calculation mistake. Hence deleting my previous answer. Here is the new answer 8*(8/3+1/3). I hope this is correct

[divya_sanam]

1..a factory manufacturing flywheels for racing cars has 10 machines to make them.the manufacturer knows the correct weight for a fly wheel.how ever one day one of the m/c begings to produce faulty parts -either overweight or under weight
.how can manufacturer find faulty m\c in only 2 weighings???

shakuntala devi 41 puzzle

2.when my uncle in madura died recently he left will instructing his executers to divide his estate of rs 1920000 in this manner:- every son should get 3 times as a daughter and evry daughetr should get 2 times as much as their mother.
whatz my aunty's share
Ans49200 10/13 shakuntala sum 25 plz explain how?

fifty min ago it was 4 times as many min past 3oclock ,how many times is it to 6o clck?
ans 26 how?

[warrior]

Originally Posted by divya_sanam

1..a factory manufacturing flywheels for racing cars has 10 machines to make them.the manufacturer knows the correct weight for a fly wheel.how ever one day one of the m/c begings to produce faulty parts -either overweight or under weight
.how can manufacturer find faulty m\c in only 2 weighings???

shakuntala devi 41 puzzle

you can find it out in one weighing if you have digital weighing machine

[catfollower]

Originally Posted by divya_sanam

1..a factory manufacturing flywheels for racing cars has 10 machines to make them.the manufacturer knows the correct weight for a fly wheel.how ever one day one of the m/c begings to produce faulty parts -either overweight or under weight
.how can manufacturer find faulty m\c in only 2 weighings???

shakuntala devi 41 puzzle

2.when my uncle in madura died recently he left will instructing his executers to divide his estate of rs 1920000 in this manner:- every son should get 3 times as a daughter and evry daughetr should get 2 times as much as their mother.
whatz my aunty's share
Ans49200 10/13 shakuntala sum 25 plz explain how?

fifty min ago it was 4 times as many min past 3oclock ,how many times is it to 6o clck?
ans 26 how?

Ans for the first prob >>>>>>>>>

Assume the weight of each non defective object(flywheel) to be 'w'.
We have 10 machine producing the objects out of which let mth (m=1 to 10) machine is defective producing objects of weight 'w +/- k'. (under/over weight)
k is value which deviates from desired value w.

ie mth machine = defective machine

STEP1:


Now in first step take 2^m objects for mth machine ie 2^1 objects produced by machine1, 2^2 by machine2,....,2^m by mth machine,...,2^10 objects by machine10.


When we gather all these objects produced by different machines and measure their total weight it will be=
=2^1*w+2^2*w+......+2^m*(w+/-k)+....+2^10*w
=2^1*w+2^2*w+......+2^m*w+.....2^10*w (+/-)2^m*k
=(2^1+2^2.....+2^10)*w (+/-) 2^m*k
since this is measured in first step this value is known let it be p

STEP2:

In second step we take 2^(11-x) objects of xth machine ie 2^10 of machine1, 2^2 of machine2,......,2^(11-m) of mth machine,etc
Like step1 we gather all objects and take their collective weight.
It will be=
=2^10*w+2^9*w+....+2^(11-m)*(w+/-k)+....+2^1*w
=(2^10+2^9+2^8+......+2^1)*w (+/-) 2^(11-m)*k
again this is known value let it be q

but first term of both eqns is (2^1+....+2^10)
this equals to (2^11-1) ie binary no 1111111111
this is constant value
therefore
p= constant1 (+/-) 2^m*k
and
q= constant1 (+/-) 2^(11-m)*k

ie
p` =2^m*k
q` =2^(11-m)*k

here p` q` are known values
p`=p-connstant1
now,

dividing both eqns,

p`/q` = [ 2^m*k] / [ 2^(11-m)*k]

ie p`/q`=[2^m]/[2^(11-m)]

solving above eqn,

2^(2*m) =(p`/q`)*2^11

from this we can get value of m as (p`/q`) is ratio of known values.

here m is the rank of machine producing defective objects.
So we have found machine.

[divya_sanam]

<OL style="MARGIN-TOP: 0in; FONT-FAMILY: arial" type=1><LI class=MsoNormal style="MARGIN: 0in 0in 0pt">A man fixed an appointment to meet Mr.X, X asked him to meet two days after the day before the day after tomorrow. Today is Friday. Whats the appointed day. --><FONT size=2> 3 marks

[rajat_nda]

Originally Posted by divya_sanam

<OL style="MARGIN-TOP: 0in; FONT-FAMILY: arial" type=1><LI class=MsoNormal style="MARGIN: 0in 0in 0pt">A man fixed an appointment to meet Mr.X, X asked him to meet two days after the day before the day after tomorrow. Today is Friday. Whats the appointed day. --><FONT size=2> 3 marks

"monday"-- go in reverse...

p.s. -- i don't think dis can come..even if my ans is wrong

[sabby2066]

hey any one can help me.....

i can't solve the folowing problems of shakuntala devi...


Q:A man i know ,who lives in my neighbourhood.travels to chinsura everyday from his work. his wife drives him over to howrah station every morning and in the eveinig exactly
at 6:00 pm.she picks up from the station and takes back home.
one day he was let off at work an hour earlier,and so he arrived at the howrah station at 5:00pm instead of 6:0 pm. he started walking home.however he met his wife enroute to the station and got in the car. They drove him arriving 10 minutes earlier than usual.
how long did the man have to walk,before he picked up his wife?



Q: 27 shakuntala devi: Down the Escalator.

Q: 60 The problem of lilawati
Q: 148 The two trains///



i m waiting for the answers , i hope that u can post the answers asa quickly as possible...

thanks in advance

[divya_sanam]

[quote=sabby2066]hey any one can help me.....

i can't solve the folowing problems of shakuntala devi...


Q:A man i know ,who lives in my neighbourhood.travels to chinsura everyday from his work. his wife drives him over to howrah station every morning and in the eveinig exactly
at 6:00 pm.she picks up from the station and takes back home.
one day he was let off at work an hour earlier,and so he arrived at the howrah station at 5:00pm instead of 6:0 pm. he started walking home.however he met his wife enroute to the station and got in the car. They drove him arriving 10 minutes earlier than usual.
how long did the man have to walk,before he picked up his wife?

Ans:- today they reached 10 minutes earlier therefore 10 minutes saved by woman who mte her husband at point A so = she saves x minutes while going to to howrah stn from the point A they met + x more minutes for comig back from howrah to that point A where she met his husband.so 2x= 10 so x=5 Therefore the point they met must have been 5 min driving time from howrah,so wife should have been at that point at 5 minutes to 6 i.e 5.55,since man strated at 5oclock so he walked till 5.55 and then met his wife so he had to walk for 55 min b4 he was picked up by his wife

Q: 27 shakuntala devi: Down the Escalator.

the solutions to the escalator problems were sent by suresh chk these to get an ide as how to solve.

A person walking takes 26 steps to come down on a escalator and it takes 30 seconds for him for walking. The same person while running takes 18 second and 34 steps. How many steps are there ??
Sol:
Let's suppose that escalator moves n steps/sec.
It is given that if he walks he takes 30 sec and covers 26 steps.
So in that 30 sec escalator would have covered 30n steps.
Hence the total number of steps on the escalator is 26 + 30n----(1)

Similarly when he runs he takes 18 sec and covers 34 steps.
So in 18 sec escalator covers 18n steps.
Hence total steps on the escalator must be 34 + 18n-------(2)

Equating (1) & (2) 26 +30n = 34 + 18n we get n= 2/3
Hence no. steps is 26+30(2/3) = 46.

Problem #2
An escalator is descending at constant speed. A walks down and
takes 50 steps to reach the bottom. B runs down and takes 90 steps
in the same time as A takes 10 steps. How many steps are visible
when the escalator is not operating?

Sol: Lets suppose that A walks down 1 step / min and
escalator moves n steps/ min
It is given that A takes 50 steps to reach the bottom
In the same time escalator would have covered 50n steps
So total steps on escalator is 50+50n.

Again it is given that B takes 90 steps to reach the bottom and time
taken by him for this is equal to time taken by A to cover 10 steps i.e
10 minutes. So in this 10 min escalator would have covered 10n steps.
So total steps on escalatro is 90 + 10n

Again equating 50 + 50n = 90 +10n we get n = 1
Hence total no. of steps on escalator is 100.

Problem #3
There is a escalator and 2 persons move down it. A takes 50 steps and B takes 75 steps while the escalator is moving down. Given that the time taken by A to take 1 step is equal to time taken by B to take 3 steps, find the no. of steps in the escalator while it is staionary.

Sol: Let A take 1 step/min.
Hence B takes 3 steps/min. Let the escalator take n steps/min
Given that A takes 50 steps and hence in the same time escalator will
take 50n steps. So total no. of steps must be 50 + 50n

It is given that B takes 75 steps (which means he takes 25 min)
So in the same time escalator will cover 25n steps.
Hence no. of steps must be 75 +25n

Equating 50+50n = 75+25n we get n = 1.
Hence total no. of steps must be 100.
I hope my answers are correct and my explanation is lucid
__________________
Regards,
Suresh.



Q: 60 The problem of lilawati

she says u will get the answer by backtracking,it would be nice if anybody gives the steps for back tracking.



Q: 148 The two trains///
Ans:--- for the 2 trains A and Bsum actually therez a formula which says if the 2 tarins which start at same time and meet at a point after which ie aftr crossing they take a and b times respectively to reach their destiantion,then since distance s same so ratio of speeds is speed A:speed B=sqrt(b):sqrt(a).So the first train is twice as fast.

Can anybody post the prrof of this formula??


All the Best and loads of luck,I think u 2 have ure infy exam on 16th.
reagards
divya

[divya_sanam]

2.when my uncle in madura died recently he left will instructing his executers to divide his estate of rs 1920000 in this manner:- every son should get 3 times as a daughter and evry daughetr should get 2 times as much as their mother.
whatz my aunty's share
Ans49200 10/13 shakuntala sum 25 plz explain how?

if the number of sons and daughters is not given how can we find the share of mother plz expalin the sum if anybody knows...

q2 >14 in is A corresponds 36 in B
133 in A corresponds to 87 in B
find the point when both the values is same I mean
x in A=x in B find x

plz post reply how to solve such sums

[NISHA9]

hi all

please explain the sol. of the qo. sqrt12+ sqrt12 + sqrt12+.......