1. N persons stand on the circumference of a circle at distinct points. Each possible pair of persons, not standing next to each other, sings a two-minute song one pair after the other. If the total time taken for singing is 28 minutes, what is N?[CAT 2004]





Write Comment

Type in
(Press Ctrl+g to toggle between English and the chosen language)

Comments

  • By: anil on 05 May 2019 02.30 am
    Total number of pairs is $$^{N}C_2$$. Number of pairs standing next to each other = N. Therefore, number of pairs in question = $$^{N}C_2$$ - N = 28/2 = 14. If N = 7, $$^{7}C_2$$ - 7 = 21 - 7 = 14. N = 7.
Tags
Show Similar Question And Answers
QA->What is the total earnings of a worker from the following data? Standard time for completing the job 50 hours. Actual time taken for completing the job 45 hours. Time rate is Rs.20 per hour, premium bonus is 60% of time saved.....
QA->A car during its journey travels 30 minutes at the speed of 40 km/hr. another 45 minutes at the speed of 60 km /hr and for two hours at a speed of 70 km/hr. Find the average speed of the car?....
QA->How much the equatorial circumference is greater than the polar circumference?....
QA->One who plays, sings, paints pictures etc not for money, but for the love of it....
QA->Liz solved 24 maths problems in 15 minutes.At this rate,how many problems can she solve in 40 minutes?....
MCQ->N persons stand on the circumference of a circle at distinct points. Each possible pair of persons, not standing next to each other, sings a two-minute song one pair after the other. If the total time taken for singing is 28 minutes, what is N?[CAT 2004]....
MCQ-> Four cars need to travel from Akala (A) to Bakala (B). Two routes are available, one via Mamur (M) and the other via Nanur (N). The roads from A to M, and from N to B, are both short and narrow. In each case, one car takes 6 minutes to cover the distance, and each additional car increases the travel time per car by 3 minutes because of congestion. (For example, if only two cars drive from A to M, each car takes 9 minutes.) On the road from A to N, one car takes 20 minutes, and each additional car increases the travel time per car by 1 minute. On the road from M to B, one car takes 20 minutes, and each additional car increases the travel time per car by 0.9 minute. The police department orders each car to take a particular route in such a manner that it is not possible for any car to reduce its travel time by not following the order, while the other cars are following the order. How many cars would be asked to take the route A-N-B, that is Akala-Nanur-Bakala route, by the police department?
 ....
MCQ-> Study the following information carefully and answer the questions given below :Ten persons - L, M, N, O, P, Q, R, S, T and U - are standing in a straight line facing north, but not necessarily in the same order. Four persons are standing between Q and S. P is standing at one of the extreme ends. L is standing to the immediate right of Q. L is standing second to the left of P. U is standing second to the right of S and second to the left of N. Three persons are standing between R and M. O is not standing at any extreme end of the line. M is far away from O than that of P.Who among them standing at extreme left end ?
 ....
MCQ-> Each of the questions below consists of a question and two statements numbered I and II given below it. You have to decide whether the data provided in the statements are sufficient to answer the question. Read both the statements and answer the below questions a: if the data in Statement I alone are sufficient to answer the question, while the data in Statement II alone are not sufficient to answer the question. b: if the data in Statement II alone are sufficient to answer the question, while the data in Statement I alone are not sufficient to answer the question. c: if the data either in Statement I alone or in Statement II alone are sufficient to answer the question. d: if the data even in both Statements I and II together are not sufficient to answer the question. e: if the data in both Statements I and II together are necessary to answer the question.How many persons are there in a straight line who are facing North ?I. L is standing exactly in the middle. L is an immediate neighbor of both A and O. Two persons are standing between A and T. T is standing at the second position from the left end of the line. B is standing at the extreme left end of the line. II. J is standing at the second position from the right end of the line. Five persons are standing between J and F. There are two persons between F and K. K is at one of the extreme ends of the line.....
MCQ-> Answer the questions based on the following information. In a motor race competition certain rules are given for the participants to follow. To control direction and speed of the motorists, guards are placed at different signal points with caps of different colour. Guard with red cap indicates the direction of participant’s movement and guards with green cap indicates the speed of the participant’s movement. At any signal point presence of three guards, two guards and one guard with red cap means the participant must stop, turn left and turn right respectively. Signal points with three guards, two guards and one guard with green cap means the participants must move at 10, 4 and 2 km/hour respectively. Kartikay, one of the participants, starts at a point where his car was heading towards north and he encountered signals as follows: at start point one guard with green cap; after half an hour two guards with red cap and two guards with green cap at first signal; after fifteen minutes one guard with red cap at second signal; after half an hour one guard with red cap and three guards with green caps at third signal; after 24 minutes two guard with red cap and two guards with green cap at fourth signal; after 15 minutes three guard with red cap at fifth signal. (Time mentioned in each case is applicable after crossing the previous signal).Total distance travelled by Kartikay from starting point till last signal is:
 ....
Terms And Service:We do not guarantee the accuracy of available data ..We Provide Information On Public Data.. Please consult an expert before using this data for commercial or personal use
DMCA.com Protection Status Powered By:Omega Web Solutions
© 2002-2017 Omega Education PVT LTD...Privacy | Terms And Conditions