Official Quant thread for CAT 2013

1.Shaurya and Ajit take a straight route to the same terminal point and travel with constant speeds. At the initial moment, the positions of the two and the terminal point form an equilateral triangle. When Ajit covers a distance of 80 km, the triangle becomes right-angled. When Arjit was at a distance of 120 km from the terminal point, Shaurya arrived at the point. Find the distance between them at the initial moment assuming that there are integral distances throughout the movements described.
(a) 300 km
(b) 240 km
(c) 200 km
(d) 225 km
(e) 275 km

2.Mrinalini and Neha travel to Connaught place along two straight roads with constant speeds.
At the initial moment, the positions of Mrinalini, Neha and Connaught place form a right triangle. After Mrinalini travelled 30 km,the triangle between the points became equilateral. Find the distance between Mrinalini and Neha at the initial moment if at the time Mrinalini arrived at Connaught place, Neha had to cover 6.66 km to reach Connaught place
a 10*3^1/2 b 12*3^1/2 c.30*5^1/2 d none




@TootaHuaDil said:
(6)
123456789101112131415161718192021222324252627.......upto4041424344 div by 45? what will be the quotient and remainder?
Remainder 4..???
@IIM-A2013 said:
1.Shaurya and Ajit take a straight route to the same terminal point and travel with constant speeds. At the initial moment, the positions of the two and the terminal point form an equilateral triangle. When Ajit covers a distance of 80 km, the triangle becomes right-angled. When Arjit was at a distance of 120 km from the terminal point, Shaurya arrived at the point. Find the distance between them at the initial moment assuming that there are integral distances throughout the movements described.(a) 300 km(b) 240 km(c) 200 km(d) 225 km(e) 275 km2.Mrinalini and Neha travel to Connaught place along two straight roads with constant speeds. At the initial moment, the positions of Mrinalini, Neha and Connaught place form a right triangle. After Mrinalini travelled 30 km,the triangle between the points became equilateral. Find the distance between Mrinalini and Neha at the initial moment if at the time Mrinalini arrived at Connaught place, Neha had to cover 6.66 km to reach Connaught placea 10*3^1/2 b 12*3^1/2 c.30*5^1/2 d none
1. b) 240 ?

s1/80 = s2/(x)
s1/(d - 120 - 80) = s2/(d - x)

80/(d - 200) = x/(d - x)
80d - 80x = dx - 200x
80d = dx - 120x
x = 80d/(d -120)
Put d = 240
x = 160


2. None?
Distance between Neha and Connaught place = d
30 = 2d - d + a = d + a
s1/a = s2/30
s1/(d-a-6.66) = s2/(d - a)
a/(d-a-6.66) = 30/(d-a)
a(d-a) = 30(d-a) - 200
(30-a)(d-a) = 200
(d)(d-a) = 200

Required distance will be d*sqrt(3)
From options:
d = 10 => a = -10
d = 12 => a = 12 - 200/12 = 12 - 16.66 = -4.66
So none of the given options match.



@TootaHuaDil said:
(1) All the divisors of 360, including 1 and the number itself, are summed up. The sum is 1170. What is the sum of the reciprocals of all the divisors of 360?
take a small case of 12= 2^2 * 3
no f factors = 3 * 2 = 6 (1,2,3,4,6,12)
sum f reciprocals = 1+1/2+1/3+1/4+1/6+1/12 = 1+2+3+4+6+12/12= 28/ (12)
= sum of the factors / nuber itself
same for 360360 = 2^3 * 3 * 5
sum f factor = 1170
sum f reciprocals = 1170/ (360)

Edited

@TootaHuaDil said:
(2) How many integers between 1 and 1000, both inclusive, can be expressed as the difference of the squares of two non negative integers?
all odd numbers & number divisble by 4 can be expressed as difference of the squares of two numbers.

example -

7 = 4^2 - 3^2

9 = 5^2 - 4^2 & so on.

similar way u can check for all multiples of 4

total numbers = odd no + multiples of 4

= 500 + 250 = 750
@TootaHuaDil said:
(6) 123456789101112131415161718192021222324252627.......upto4041424344 div by 45? what will be the quotient and remainder?
is R = 19?
If yes than i wud explain.
@TootaHuaDil said:
(1) All the divisors of 360, including 1 and the number itself, are summed up. The sum is 1170. What is the sum of the reciprocals of all the divisors of 360?
divisor of 360 are 1,2,3,4......360
now, sum of reciprocal of divisor is
=>1/1 +1/2 +1/3 + 1/4 +................................ + 1/360
=>1/360 * (360/1 +360/2 +360/3 + .......................360/360)
=>1/360* (360 +180 +120 + + 3 + 2 + 1)
=>1170/360=3.25

find the area of the equation |x+3|+|x+2|


Also can you please explain the algorithm. Thanks in advance.
@poornaveturi either data insufficient or question is wrong or area is infinite..........solve it any way you get all equations in 'x' i.e. all lines parallel to y axis and no line parallel or inclined to axis this makes an open figure and area of open figure is infinite.................
@poornaveturi said:
find the area of the equation |x+3|+|x+2|Also can you please explain the algorithm. Thanks in advance.
are u sure the question is correct? because a linear inequation cannot enclose an area
@techgeek2050 Sorry |x+3|+|y+2|
@poornaveturi said:
@techgeek2050 Sorry |x+3|+|y+2|
is it 2592 ?

@techgeek2050 The answer for this question hasnt been given correctly in the solution book...it says 24 pie...can u explain the algorith plz?
@poornaveturi said:
@techgeek2050 The answer for this question hasnt been given correctly in the solution book...it says 24 pie...can u explain the algorith plz?
the area is not altered if u shift the origin to any other point. in this case you can shift the origin to (3,2)
the equation will become --- |X| + |Y|
which will form a square with side 36x(2)^0.5
so area will be 2x36^2 = 2592
@poornaveturi said:
@techgeek2050 Sorry |x+3|+|y+2|
2592
The graph forms a square with opposite vertices as (-3,34), (-3,-38) and (-39, -2), (33,-2).
@techgeek2050 what if it had been not a perfect square then?
@poornaveturi said:
@techgeek2050 what if it had been not a perfect square then?
|x| + |y| = k will always form a square.
u can check by drawing the lines ---
x + y = k
x - y = k
-x + y = k
-x - y = k

I hope this won't be counted as spamming. All CAT 2013 aspirants please join this thread. We need to run this thread for overall prep of CAT. And please quant masters post some questions there also. 😃
http://www.pagalguy.com/forums/prep-resources/cat-2013-prep-t-94066/p-3622166?page=1

@TootaHuaDil good call! the DI LR thread was literally dead.

A person sells 20 kg s at 400 .A customer asks for 20 % discount and he agrees to it,but instead of 1 kg he gives 4 % less.what is the effective discount that the customer gets?


thanks in advance