Another old trick


There are 6 slots filled with 1 , 0 in the above order.Now you can operate on any two adjacent sectors and increase the values of both by 1 at a time.you can change the values of two adjacent sectors only at a time.Is it possible that after a sequence of operations al the sectors possess the same value ?

2 Answers

1
Rohan Ghosh ·

It is a problem of invariance

let a,b be two adjacent elements

after carrying out the operation they become
a+1,b+1

now, there are three sectors in the whole circle .

hence if we consider a and b as a part of one sector .

we get the summation of difference between the two elements of each subset=
a+1-b+1+..=a-b+...=unchanged

if we consider a and b part of different sectors

we get still

x-(a+1)+b+1-y+...=a-b+...=unchanged

when all the elements will be equal then the sum will be =0+0+0=0

but initial sum=1-0+1-0+0-0=2
but it should be invariant
..

hence CONTRADICTION ..

62
Lokesh Verma ·

There's a much simpler solution..

the sum of even slots and odd slots be P and Q respectively.

Whenever we add 1 to 2 consecutive slots... P and Q both increase by the same number..

So P-Q remains constnat..

and equal to 2 no matter what.

Hence ... :)

Your Answer

Close [X]