Official Quant thread for CAT 2013

MBA CAT 2024
32798

A party of n persons sit at a round table.No of ways in which 2 specified persons never sit next to each other??

My approach: Frst person in any of the n seats. Second person cant sit on the 2 adj seats.therefore second person has n-3 seats to choose from.Remaining n-2 arranged in n-2 ! ways
hence, n* (n-3)* (n-2)!

Answer given- (n-1) ! - (n-2) !
What cases am I missing or including so as to deviate from the correct answer????
32799

Simple but Tricky !


Q. Two rifles are fired from same place at a difference of 11 minutes and 45 seconds. But a man who is coming toward that place in a train hears the second sound in 11 minutes. What is the speed of train.

A 81 Km/Hr

I have this explanation which says distance travelled by sound in 45 second = distance travelled by train in 11 minutes. i.e. 81 km/h


Can anybody tell the approach ?? or the above explanation how that happend ?? 😠
32800

Rahim sets out to cross a forest. On the first day, he covers 1/10th of the journey. On the second day he covers 2/3rd of the journey he travelled first day.He continues in this manner alternating the dayin which he travelled.At the end of the seventh day he finds that 22 1/2 km more is remaining. How wide is the forest /?


A. 66 2/3 km
B. 100 km
C. 120 km
D. 150 km
32801

X and Y run a race of 2000m. 1st X gives Y a start of 200m & beats him by 30 secs. next, X gives Y a start of 3 mins and is beaten by 1000 m. find the time in mins in which X and Y can run the race separately? gv d soln too frnds 😃

  • 5,9
  • 8,10
  • 4,5
  • 6,9

0 voters

32802

unit digit in the expression (36^234 x 33^512 x 39^180) - (54^29 x 25^123 x 31^512) is______? how?

  • 6
  • 8
  • 5
  • 0

0 voters

32803

A class of 24 boys was divided into two sub-sections containing 12 boys each. What is the probability that the two shortest boys of the class are in different sub-sections, if all boys have different heights?(1)7/24(2)6/23(3)12/23(4)14/23

32804

@barneywaitforitstinson

How many ordered sets of positive integer triples (a,b,c)are there such that a+b×c=100?



1) t



2) t Skip



×

5 sets : (1,9,11),(1,3,33),(2,7,14),(4,6,16),(4,8,12)

1+9*11
1+3*33
2+7*14
4+6*16
4+8*12

😃
32805

Find the highest power of 2 in 1! + 2! + 3! + 4! + ......... + 600!

32806

Need help on this:

Of three taps X, Y and Z, Y takes 2 times as much time as X and Z together, while X takes 20 minutes more than Y and Z together, to fill a tank. If the three taps together fill the tank in 24 minutes, then how long does X take to fill the tank individually? answer is 60 mins.

have been trying for 10 mins 😠


32807

Q1

QuantExpert - Q.O.D


32808

how many 7 digit no.s are there having the digit 3 three times and the digit 0 four times..?


a)15 b) 3^3*4^4 c)30 d) none



32809

Positive real numbers a, b, c, d, e satisfy the relation

2a+b/3+c+6d+7e=20ďťż

The maximum value of the product abcde be isp/q, where p and, q are relatively prime natural numbers. What is the value of (p + q)?


Courtesy test Funda...answer not sure

ďťż
  • 1031
  • 263
  • 71
  • None of these
  • 256

0 voters

32810

In a fruit shop there are 4 baskests containing apple,mango,orange banana.Every customer who comes to the shop buys atleast one and atmost 11 fruits.If on a particular day all customers buy different number of fruits find the max no of customers that day.

32811

O is the centre of the circumcircle of the quadrilateral ABCD. The equal diagonals of ABCD intersect at O. The perpendicular distance from A to diagonal BD is 4cm and are of the circle is 25pie sqcm. Find the perimeter of ABCD.
1. 12root5, 2. 16root5, 3.25root5 d. None

32812
@chillfactor x^3-x-1=0 , find the real value of x (only 1 possible) help? Not from any site
32813
Climbing up an escalator going down, Ram takes 60 minutes to reach from ground floor to first floor. Climbing down on same escalator going down, Ram takes 30 minutes to reach ground floor from first floor. How many minutes will Ram take to reach first floor from ground floor if the stairs were still ?
My soln.
speed of escalator= V
speed of Ram= U
Since distance is same in all 3 cases,
t= 60 min. ; Speed = U-V
t= t min. ; Speed = U
t= 30 min. ; Speed = U+V
Since Speeds are in AP, Times will be in HP.
Thus, t= 2*30*60/(30+60)
Is this approach correct ?
32814

@Tusharrr

@chillfactor x^3-x-1=0 , find the real value of x (only 1 possible) help? Not from any site



32815

if x & y are two even integers then , the total no of solutions for the equation is
x^2 - y^2 = 7389746232 is

  • 0
  • more than 2
  • 2
  • 1

0 voters

32816

This is the question:

4. Minimum value of |5-x| + |x-1.2| + |x+2.8|.

7.8

8.8

8.6

6.8



32817

N = 3! + 4! + 5!+ ........... + 64!
then which of the following is true regarding N

  • neither A nor B
  • N is a perfect square
  • N is a perfect cube
  • both A & B

0 voters