There are seven thieves, They steal diamonds from a diamond merchant and run away in jungle. While running, night sets in and they decide to rest in the jungle When everybody’s sleeping, two of the best friends get up and decide to distribute the diamonds among themselves and run away. So they start distributing but find that one diamond was extra. So they decide to wake up 3rd one and divide the diamonds again …..only to their surprise they still find one diamond extra. So they decide to wake up fourth one. Again one diamond is spare. 5th woken up……still one extra. 6th still one extra. Now they wake up 7th and diamonds are distributed equally.
How many minimum diamonds they steal?
Check your answer:-
See Solutionand
x = 1 + N1*2;
x = 1 + N2*3;
x = 1 + N3*4;
x = 1 + N4*5;
x = 1 + N5*6;
x = N6*7;
where N1, N2, N3, N4 and N5 are integers.
From above we can also say
N1*2 = N2*3 = N3*4= N4*5 = N5*6 = y
Now y should be divisible by 2, 3, 4, 5 and 6, its nothing but common multiple of all.
LCM of 2, 3, 2*2, 5, 2*3 => 2*3*2*5 => 60
at the same time common multiple + 1 should be divisible by 7 as well.
60 + 1 is not divisible by 7
120(60*2) + 1 is not divisible by 7
180(60*3) + 1 is not divisible by 7
240(60*4) + 1 is not divisible by 7
300(60*5) + 1 is divisible by 7
Thus they must have stolen minimum 301 diamonds.
Prashanth vunnam says
I found formula for this
x=3
43, x43, x043, x0043,x00043………xn43
those all possible cases we will get
Explanation
7*43=301 , 7*343=2401 and 7*3043=21301 …….so on all numbers give the answer
Aneesh Satheesan says
ANS: 301
150 * 2 +1=301
100 * 3 +1=301
75 * 4 + 1=301
60 * 5 + 1=301
50 * 6 + 1=301
43 * 7 =301
nibin says
91,721.. these are also correct
Gaurav k says
@nibin 91 cannot be divided equally into 4 + 1
91/4 = 22 + ‘3’ so when 91 is divided among 4 people sintead of 1, 3 are getting left
Anne J says
60x + 1 = 7y
7y must end with 1. (since 7y-1 should be divisible by 5 and 2 at the same time; i.e, 7y-1 should
be divisible by 10, or 7y must end with 1 )
hence y should end with 3 (no other digit can make 7y end with 3)
7y should be greater than 61
Trial and Error:
7(3)<61
7(13)= 91; 90 not divisible by 60
7(23)=161; 160 not divisible by 60
7(33)=231; 230 not divisible by 60
7(43)=301; 300 divisible by 60
@viccky says
but it can be 2401……???
Gaurav k says
How many ‘minimum’ diamonds they steal? we need to find out the minimum in this question