Submitted Questions

  • Pick the Winner Correctly

    For the FIFA world cup, Paul the octopus has been predicting the winner of each match with amazing success. It is rumored that in a match between 2 teams A and B, Paul picks A with the same probability as A's chances of winning.Let's assume such rumors to be true and that in a match between X and Y, X the stronger team has a probability of 2/3 of winning the game. What is the probability that Paul...

  • Dart Problem

    A circular dart board of radius 1 foot is at a distance of 20 feet from you. You throw a dart at it and it hits the dartboard at some point X in the circle. What is the probability that X is closer to the center of the circle than the periphery?


    • Oct 13th, 2014



    • Dec 27th, 2013


  • 5 digit number divisible by 4

    How many 5 digit numbers can be formed using the digits 1, 2, 3, 4, 5 (but with repetition) that are divisible by 4?


    • Oct 13th, 2011

    Divisibility rule of 4 is last two digits are divisible by 4 so in 5 digit no last two digit should always be 12,24,32,44,52; (any one of them may be) so for last two digits 5 ways are possible ; si...

  • Planet Corba

    On planet Corba, a solar blast has melted the ice caps on its equator. 8 years after the ice melts, tiny plantoids called echina start growing on the rocks. echina grows in the form of a circle and the relationship between the diameter of this circle and the age of echina is given by the formulad = 4 * √ (t - 8) for t ≥ 8where d represents the diameter in mm and t the number of years since the...


    • Oct 18th, 2011


  • Circular Handshake

    36 people {a1, a2, ..., a36} meet and shake hands in a circular fashion. In other words, there are totally 36 handshakes involving the pairs, {a1, a2}, {a2, a3}, ..., {a35, a36}, {a36, a1}. Find the size of the smallest set of people such that the rest have shaken hands with at least one person in the set.


    • Nov 25th, 2012

    2y+x-3z=6; x+4y-2z=10; x+2y+6z=24

    harsh kumar

    • Sep 18th, 2012


  • Points on Plane

    Given a collection of points P in the plane, a 1-set is a point in P that can be separated from the rest by a line; i.e. the point lies on one side of the line while the others lie on the other side. The number of 1-sets of P is denoted by n1(P). Find the maximum value of n1(P) over all configurations P of 10 points in the plane.

  • Sheet of Paper

    A sheet of paper has statements numbered from 1 to 35. For all values of n from 1 to 35, statement n says "At most n of the statements on this sheet are false". Which statements are true and which are false?

  • Min-Max Game

    A and B play the following min-max game. Given the expressionN = 12 + X*(Y - Z)where X, Y and Z are variables representing single digits (0 to 9), "A" would like to maximize N while "B" would like to minimize it. Towards this end, "A" chooses a single digit number and "B" substitutes this for a variable of her choice (X, Y or Z). "A" then chooses the next value and "B", the variable to substitute the...

  • 1/3 of a Number

    1/3 of a number is 3 more than 1/6 of the same number. What is the number?


    • Oct 20th, 2011


    shalini gupta

    • Oct 7th, 2011

    Let no is x
    so i/3 of a no is x/3
    and now form the equation according the given language in question
    By solving this equation x=18 so no is 18