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Numerical Ability
Number System
Some people are standing square. From them 32 are removed and then form a small square and
then 8 more removed. now we cannot form the square. so how many people are there at the
beginning?
Read Solution (Total 7)
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- 81
We should find the two square numbers whose difference is 32. Starting from 9,16,25,36,49,64,81,100,....
We observe 81-49=32 & 49-8=41 which is not a square. - 9 years agoHelpfull: Yes(18) No(13)
- If we take each side 10students,then it will be 40 and when we remove 32 we have only 8 students means each side 2 will be there, if we remove 8 too then there is no square to form.
- 9 years agoHelpfull: Yes(6) No(3)
- for such questions always try to cross check the options.
let initially x^2 people were standing in the square and after removal of 32 people from this new square becomes y^2. therefore x^2-32=y^2 or x^2-y^2=32 or (x+y)(x-y)=32
but 32=1*32 or 2*16 or 4*8 so (x+y)(x-y)= 1*32 or 2*16 or 4*8
now x+y= 32 or 16 or 8
x-y= 1 or 2 or 4
find the solution in each case and check which one of these satisfies the condition. the one which satisfies all the condition given in the question is answer. - 9 years agoHelpfull: Yes(1) No(1)
- correct explanation plzz....
- 9 years agoHelpfull: Yes(0) No(0)
- no solution
- 8 years agoHelpfull: Yes(0) No(0)
- Ans : 40
Explanation :
Let n be the initial number of people.
These n people form a square.
Now 32 people are removed.
Therefore now number of people = n - 32.
Now again 8 people are removed from n - 32 people => now people remained = n - 40.
Now we cannot form a square with these n - 40 people.
Here we cannot forming a square means that no of people = 0
i.e, n - 40 = 0
so n = 40.
Thus initial number of people = 40. - 7 years agoHelpfull: Yes(0) No(0)
- 9,16,25,36,49,64,81
49=49-32-8= 9 which is square
64=64-32-8=24.which is not square - 7 years agoHelpfull: Yes(0) No(0)
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