Elitmus
Exam
Numerical Ability
Number System
If w and x odd numbers,y and z even numbers then
1/8[(w^2+x^2)*(y^2+z^2)]
A.always odd
B.always even
C.may be both
D.not an interger
Read Solution (Total 22)
-
- Let,
w = 1(odd), x = 3(odd)
y = 2(even), z=4(even)
we get
1/8* { ( 1 + 9 ) ( 4 +16 ) }
1/8 * { 10 * 20 } = 25 [which is odd]
now,
If we take
w = 1(odd), x = 3(odd)
y = 12(even), z = 20(even)
we get,
1/8 * { ( 1 + 9 ) ( 144 + 400 ) }
1/8 * { (10) (544) } = 680 [which is even]
The value can be even and can be odd.
So, the ans is C. - 10 years agoHelpfull: Yes(48) No(1)
- Let w=3, x=5
y= 2, z=4
Solve for the given equ-
1/8* [(w^2+x^2)*(y^2+z^2)]
You will get odd no. not a fraction. (Always)
So, A is correct option. - 10 years agoHelpfull: Yes(3) No(9)
- This is correct that product of two term always gives even but after dividing 8 it is not sure that the out put will be even only or odd only so,
after checking all the possibility Option C is correct. - 10 years agoHelpfull: Yes(3) No(0)
- odd*odd=odd => w^2 & x^2 are odd
odd+odd= even => w^2 + x^2 is even-----1
even*even=even => y^2 & z^2 are even
even+even=even => y^2 + z^2 is even-----2
now 1+2 i.e even +even = even
Now even/8 = even or odd
u can check by putting values like
8/8=1 - 9 years agoHelpfull: Yes(3) No(0)
- D) not an integer because it will always be a fraction
- 10 years agoHelpfull: Yes(2) No(6)
- Option should be C.
When I cheked by putting the values, then I got it may be both an even number or an odd number. - 10 years agoHelpfull: Yes(2) No(0)
- A) Always odd
- 10 years agoHelpfull: Yes(1) No(2)
- a is correct answer.
- 10 years agoHelpfull: Yes(1) No(2)
- Always odd answer a) is correct
- 10 years agoHelpfull: Yes(1) No(2)
- may be both...
- 9 years agoHelpfull: Yes(1) No(0)
- how shruti
- 10 years agoHelpfull: Yes(0) No(0)
- B will be the right option check by putting the value in the position.
- 10 years agoHelpfull: Yes(0) No(2)
- try with these,
13, 17 and 56, 2
u will get a fraction... so D is right option.... - 10 years agoHelpfull: Yes(0) No(7)
- Shruti can u explain ur answer??
- 10 years agoHelpfull: Yes(0) No(0)
- Always even
- 10 years agoHelpfull: Yes(0) No(1)
- guys this kind of question quite easy to solve just consider different values odd and even and u can verify it it will always be odd;
- 9 years agoHelpfull: Yes(0) No(2)
- If this equation is under the 1 ,then always be a fraction number it is. then option D is perfect. am agree with shruti.
- 9 years agoHelpfull: Yes(0) No(0)
- option d is correct when 1 is divided by any no it gives ans in decimal or fraction so in this ques 1/8[......] not a integer.
- 9 years agoHelpfull: Yes(0) No(0)
- since , even * even=even;
odd * odd=odd;
even + even= even;
odd+ odd=even;
but even/even or even/odd or odd/even or odd/odd may be even may be odd and may be its not an integer.
these concept is applied here;
now you can find result..Answer : (D) - 9 years agoHelpfull: Yes(0) No(0)
- putting different values of w,x, y,z answer is may be even ,odd or for some values it is not a integer it comes out fraction
- 9 years agoHelpfull: Yes(0) No(0)
- (Odd+odd)*(even+even)/8
Even *even /8
Always even - 9 years agoHelpfull: Yes(0) No(0)
- (Odd+odd)*(even+even)/8
Even *even /8=even/8
so it may be odd or even=option c - 8 years agoHelpfull: Yes(0) No(0)
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