Neha's *Fundu* Section

[rajsher]

grt work neha.
u have set the trend and v hv seen a lot of contributors adding up.
cheers to aalll of yaaaaa.

[prabal arora]

Neha i m very new to cat as u can say a starter plz i cant get it all plz let me knw abt ur table plzzzzzzzzzzzzz


Prabal
naughty_maverick@rediffmail.com

i shall be greatlful

[prabal arora]

whenever we need to do calculation of a square where at last we having the digit 5 then we can easily caalculate............

25*25=625 i.e. multiply the 10th place number i.e. 2 with its suceeding number i.e.3 .......2*3=6 and multiply 5*5=25 that means 625


85*85= 7225 i.e. 8*9=72 5*5=25 i.e. 7225


hugssssss.......
prabal

[andy4u]

this is awesome neha,u have really put in a lot of effort,thak you very much.

[axterix]

This is my first post on pagalguy.. great thread neha... the percentage table mentioned at the start of this thread .. a similar kind of table can be found in Arun Sharma's book- Quatitative Apptitude for the CAT.. check it out .. ciao

[axterix]

hmm .. just noticed the dates on Neha's posts .. been two yeaqrs.. must have passed out of NIFT by now .. well i guess this thread will last for a very long time .. cartloads of valuable questions...
great going ..
ciao

[nitesh2005]

Can u give short cuts for Q 2,4,5,6.And can anyone solve Q3.

Originally Posted by pagalneha

1. A working man has a rise of a 12.5% in his wages rate per hour. There is a drop of 8%in the number of hours worked per week. If his original weekly wages for a week of 50 hrs. was Rs. 120, find (a) his new wages per hour. (b) the percentage increase in the total weekly wages.
2. A student was asked to divide 7.5 by 8.3 and to obtain the quotient correct to 3 decimal places , but he divided 8.3by 7.5 and got the result correct to 2 decimal places . by how much % was the result wrong?
3. The incomes of A and B are in the ratio 5:3, their expenses are in the ratio 2:1> if the total annual savings of A and B are 3600 each, find the monthly income of A and B.
4. The measure of one side of a rectangle is too long by 4% of its true length and that of the other is short by 5% of its true length. Find the error % in measure obtained for the area of the rectangle.
5. The freight of a machine amounts to 20% of its price. Had the price been 10% less than what it is, the total cost of the machine would have been Rs. 480 less. What is the price of the machine?
6. Which bargain is better discount: discount series of 20%, 15% and 10% or discount series of 25%, 12% and 8%.

Answers.
1. Rs. 2.7/hr, 3.5%
2. 22.8%
3. 1500,900
4. 1.2%
5. 4000
6. 2nd.

[catasp2005]

hi nitesh,

the shortcuts wud involve taking 100 as base & then solving bcoz it is easy to calculate %age of 100.........
try doing the ques with this & if u hv any probs........do tell me.....
hey hs any1 got a diff short cut?

cheers

[Ninja]

Originally Posted by pagalneha

SIMPLE INTEREST AND COMPOUND INTEREST.


Here’s a table for calculating SI and CI
------------------ S.I. ------------- C.I.
1--------------------S -------------Upto S
2------------------2S--------------- Upto 2S+X
3------------- -----3S--------------- Upto 3S+3X+
4--------------------4S ------------ Upto 4S=6X++
5--------------------5S ------------ Upto 5S+10X+++
6-------------------6S ------------ Upto 6S+15X+++

“++” it roughly takes a value of Rs. 2 for Rs 100 of X.

Q. the difference between CI and SI is Rs 9848 at 8% interest put out for 4 yrs. What ids the principle?

Method-
For 4 yrs. The value that corresponds is 6X++
So 6X++ = 9848
Here we divide the amt. by 100 and ignore the decimal part so we get 98 and now we subtract 2 from it and now we get 96
So 6x =96 , x =16
8% of SI= 16
So 1% of SI = Rs. 2.
100% of SI =200
200 is 8 % of principle therefore the principle is 2500.
------------------------------------------------------------------------------------------------------------
Sample- What is the interest on Rs. 17250 for 3 yrs. At8% interest compounded annually?

Method- 8*3= 24
(8* /100= 0.64.
0.64*3= 1.92+ (approx. 2)
so 24+2=26%
26% of 17250= 4490
( here all the calculations can be done mentally and approximated, we generally do not need to write. This saves time. And we always have ans. options in the exam, so we can get the ans. closest to it, put we need practice for this)

Can sumbody plz explain the working method for this... especially the first Question?
Plz help...Had asked this question before but with not much help.
Thanks.
Take care

[Sharon]

Hi everyone,

Saw this section just now. An excellent peice of work. Like others I too feel that I shud have been a Pagalguy Memeber b4 cat 2004. Any way, better late than never.

I am having difficulty in understanding a particular portion, which i have highlighted. It wud be a gr8 help if anyone cud throw light on it.

Originally Posted by pagalneha

COIN CONCEPT

When 2 quantities are sold as a group together .
Here r some more fundas, with examples.


Example- A horse and a carriage were bought for Rs. 12000. the carriage was sold at a loss of 10% , horse was sold at a profit of 20%. Together I received Rs.13500. what is the C.P. and S.P. of each.

Method-Assume everything to be a horse, so I shud have sold everything at 20% profit.20% of 12000+12000= 14400.But I received Rs. 13500 only that makes a difference of 900 or Rs. 900 are less. This also makes a difference of 30% coz we calculated 40% profit (20+20%), but we had [+20%+(-10%)]=10%
I calculated 30% more on carriage.
30% or carriage=900
therefore 100%=3000
so now we have the individual cost of the horse, the carriage is for 9000/-and the S.P. can b calculated now.

We have similar questions in many forms which can b done by applying the above concept.

Bye for now.