official quant thread for cat08

[masoom]

Originally Posted by KillFRenzy

!!

Btw....in Investment question...
we are havin 3 right answres..
3:1:1, 1:1:1, 2:1:1, !! an all of them are going !!

well i think we had found particular cases..

answer should be such that..

it should satisfy every amount of sum..

and by the method of vivek in the morning...

it is coming to be 2:1:1...

@killfrenzy... PM your id to me dude ..

[shivam_01]

Originally Posted by shivam_01

carrying forward the concept of the day funda

some more questions

A radiator holds 16 litres of an antifreeze-water mixture that is 30% antifreeze. Your job is to drain just the right amount of fluid from the radiator so that when the radiator is refilled with pure antifreeze, the mixture becomes 50% antifreeze. How many litres do you need to drain?

1) 29/7 2) 30/7 3) 31/7 d) 32/7

A chemist has m ounces of salt water that is m% salt. How many ounces of salt must he add to make a solution that is 2m% salt?

1) m/(100+m)
2) 2m/(100+2m)

3) m^2/(100+2m)

4) m^2/(100-2m)

The right answer is Option (4).
Apply Alligation
For (100 – 2m) kg of salt water, we have to mix m kgs of pure salt.
For m kg of salt water, we have to mix (m/100-2m)*m kg of pure salt = m^2/(100-2m)

The right answer is Option (4).
Let x litres of 30% antifreeze is drained.
By alligation rule = 16-x/x= 5/2 = 32–2x = 5x
x =32/7

[Niki_10]

Originally Posted by vivek417

Yup...follow the rule(concept) that I have mentioned today morning....

10----(2+2)=4
8----(2+0) = 2
12----(2+0) = 2

Hence ratio = 4:2:2 = 2:1:1

Thanks
Vivek

Hi vivek,

Sorry but i could not follow ur concept.

I have seen ur earlier post for this concept even.

Can u please explain it.

[vivek417]

Originally Posted by prakharc

Someone solution?? is there some easy way...or you go about taking ratio as x:y:1 and calculating profit % ??

Prakhar...u can see the rule that I have mentioned in the morning...if it is not clear then I would try to explain it...

BTW this concept has been take from the book(Quicker Mathematics) written by M.Tyra..best book on alligation....

Thanks
Vivek

[Niki_10]

Multiple post

[hi.shivani]

Originally Posted by prakharc

Someone solution?? is there some easy way...or you go about taking ratio as x:y:1 and calculating profit % ??

see its not necessary to always apply the mathematical tool..

what the investor wants is simply the return of 10%.
Suppose the amount is Rs.100..he just want Rs.110 thats it.
Just look at the options,if we look at the option 2:1:1.
What does it mean??
means Rs.50,Rs.25 and Rs.25
Now 110%of 50 is Rs 55,108% of 25=Rs.27 and 112% of 25=28

Which add up to Rs.110
which matches the investor's condition.

[prakharc]

Originally Posted by vivek417

2) Concept 2:- I will make use of an example to illustrate the same:-

In what ratio should wheat of price Rs 227/kg, 229/kg & 232/kg should be mixed to have wheat of price 230/kg?

227 ----2 (232-230)

230---229-----2 (232-230)

232-----3+1 = 4 (230-227)+(230-229)
So ratio is 2:2:4 = 1:1:2

We would take 2 at a time such that when we use them the mixture can result in the one that we need.....227/kg & 229/kg togethar cannot result in 230/kg at any ratio...

So the subsets are (227,232) & (229,232) only....
Then we would subtract each price from the final price & put them on the other side as can be seen above(example 232-230....I have put this for 227 & 229)...same process for the rest.

Thanks
Vivek

Can you please explain how you made that table??

And also in bold part..you wrote subtract each price from final price for 227 that should be (230-227)..but you put (232-230) adjacent to 227...and why 229 and 230 in one row??

[vivek417]

Originally Posted by Niki_10

Hi vivek,

Sorry but i could not follow ur concept.

I have seen ur earlier post for this concept even.

Can u please explain it.

Well it is difficult to explain it without having any diagram....I will still have a try...

Take 2 items at a time....for example 10 & 8(investments)

Now the final profit = 10

Subtract 10 from 10(final profit) & then put this amount against 8 which is 0
Similarly subtract 8 from 10 & then put this amount against 10 which is 2

Now other groups are (8,12) & (10,12)

(12-10) ---- 2
(8-10)------2

(10-10)----0
(12-10)----2

So we have for 10......(2+2) = 4
for 8....(0+2) = 2
for 12...(2+0) = 2

Hence ratio = 4:2:2 = 2:1:1

Thanks
Vivek

[shivam_01]

Originally Posted by megs0211 (CAT 2008: Quantitative Questions a Day 1 to 50 - The discussions)
can n e plzzz solve dis....

The currency ‘Tiso’ is available in three denominational notes: 10 Tisos, 20 Tisos and 100 Tisos. In how many ways can a bill of 290 Tisos be paid?

solution 10x+20y+100z= 290

when z=1 then 10x+20y = 190 so x+2y=19
Y=1 to 9 solution set

(19,0,1).... (1,9,1)..........10 solutions

when z = 0 then
10x+20y = 290 = x+2y = 29
(29,0,0)..................(1,14,0)................ ..15 solutions

when z = 2 then
10x+20y = 90 = x+2y = 9 so the answer
(9,0,2).............(9,4,2)................. 5 solutions

so distinct ways is 30 ways

[vivek417]

Originally Posted by prakharc

Can you please explain how you made that table??

And also in bold part..you wrote subtract each price from final price for 227 that should be (230-227)..but you put (232-230) adjacent to 227...and why 229 and 230 in one row??

229 & 230 are not togethar.....actually while submitting my post...internally it does some adjustment..so its not that clear

230....in the second row is the final price while 229 is one of the price...

Every price like 227 should be subtracted from final price(230) & put against the other with which it has been paired.

Thanks
Vivek