Elitmus
Exam
Numerical Ability
Number System
Given that x and y are odd number and z is a positive even number.
Value of 1/8(x² + y²)*z² is
a) can be fractional
b) can be only odd
c) can be only even
d) can be even or odd
Read Solution (Total 39)
-
- Square of odd digit is always odd
And odd + odd = even
even * even is always even
But even/even can be even or odd
So the answer will be d
For the confirmation of the answer you can refer Arun sharma - 9 years agoHelpfull: Yes(21) No(3)
- ans -d) can be even or odd
because , if we take x=3 ,y=5 and z=2
then we get by solving 1/8(x2 + y2 )* z2 = 17 (odd no)
and again if we take x=11,y=13 and z=4
then we get from eqn=580 (even no) - 9 years agoHelpfull: Yes(6) No(1)
- (d) can be even or odd
- 9 years agoHelpfull: Yes(3) No(1)
- 1/8 *(1^2 + 3^2 ) *2^2 =2(Even)
1/8 *(3^2 + 5^2 ) *2^2 =17(Odd)
So can be even or odd...d is right answer
- 9 years agoHelpfull: Yes(2) No(0)
- case1-> take x=1,y=3,z=2
ans is 5,that is an odd no.
case2-> take x=5,y=7,z=12
ans is 1332,that is an even no.
so final ans. is CAN BE EVEN or ODD.
Option D. - 9 years agoHelpfull: Yes(2) No(0)
- d)even or odd
because even/even is not necessary to be even..
- 9 years agoHelpfull: Yes(2) No(0)
- let
case I
-
x=a(odd);
y=a+2;
z=4*a (even=4*odd) ;
=> 1/8*[a^2+(a+2)^2]*(4*a)^2
= 1/8*[a^2 +a^2+4+4a]*16*a^2
= 2*[2a^2+4a+4]*a^2
=2*any no.
= even.
Case II
-
when x=a,y=a+2& z=2a
final solution =1/2*(a^2+2a+2)*a^2
pt a=1,3,5.
always got odd.
Hence answer D - 9 years agoHelpfull: Yes(2) No(0)
- once take x=3 & 5 and y=2 and put these value and solve u ll get an odd number 17
again take x=5 & 7 and y=4 and put these value and u ll get 148 an even number
so the answer will be D) can be even or odd - 9 years agoHelpfull: Yes(2) No(0)
- answer is D (can be even or odd)
- 9 years agoHelpfull: Yes(2) No(0)
- Can be even and odd....
- 9 years agoHelpfull: Yes(2) No(0)
- simply odd*odd=odd
even*even=even
odd+odd=odd
even+even=even
so lets in problem
(odd^2+odd^2)*even^2
(odd+odd)*even*even
even*even*even
at least divide by eight but not confirm quotient is even or odd
so answer is option d - 9 years agoHelpfull: Yes(2) No(1)
- can be even or odd
assume x=5,y=7,z=6 then It is odd
assume x=5,y=7,z=4 then It is even - 9 years agoHelpfull: Yes(1) No(2)
- option d) can be even or odd
- 9 years agoHelpfull: Yes(1) No(0)
- Option a: we always get a fractional part.
- 9 years agoHelpfull: Yes(1) No(2)
- can be even or odd
odd+odd=even
even/odd=even or odd - 9 years agoHelpfull: Yes(1) No(0)
- ans is (D) can b even or odd
- 9 years agoHelpfull: Yes(1) No(0)
- I don't think so.
I have also written D i.e. Can be odd or even and It is correct. - 9 years agoHelpfull: Yes(1) No(0)
- can be only even
- 9 years agoHelpfull: Yes(0) No(2)
- square of odd number is alway odd...
odd + odd = even
even*even=even
therefore it can be only even - 9 years agoHelpfull: Yes(0) No(2)
- a option..........
- 9 years agoHelpfull: Yes(0) No(2)
- c) only even, it is absolutely right.
- 9 years agoHelpfull: Yes(0) No(3)
- It can only be even. Therefore,option (c).
- 9 years agoHelpfull: Yes(0) No(3)
- c) can be only even number
- 9 years agoHelpfull: Yes(0) No(2)
- addition of square of odd numbers will always give even number, and multipling it with square of even number will also give even number. Therefore answer is (c) can be only even.
- 9 years agoHelpfull: Yes(0) No(1)
- it will follow badmas rule and first bracket value has to be evaluated,nd then divide and them multiplicaqtion.
- 9 years agoHelpfull: Yes(0) No(0)
- option : c
can be only even
because when we add squares of odd numbers(x^2+y^2) thee result will be even number
and
when we multiply two even numbers the result will be always even number. - 9 years agoHelpfull: Yes(0) No(1)
- 1/any no (odd or even)
after dividing it becomes 0.some number..so zero is neither even not odd.
so the correct answer is a fraction
- 9 years agoHelpfull: Yes(0) No(1)
- can only be odd
put x=1,x=3
z=2(least positive value)
multiplication by any number,results in even number
so 40/5=8
try another value ,you will get answer in postive value
so answer is c) can only be even number
- 9 years agoHelpfull: Yes(0) No(2)
- a) can be fractional as u always have a no. in the form of 1/some other no.not 1
- 9 years agoHelpfull: Yes(0) No(1)
- D)can only be even
- 9 years agoHelpfull: Yes(0) No(2)
- it is even only..............
- 9 years agoHelpfull: Yes(0) No(1)
- were u sleeping nikhil at the tym of solving this question :P
- 9 years agoHelpfull: Yes(0) No(4)
- i have written d but it was wrong ..
- 9 years agoHelpfull: Yes(0) No(1)
- why won't the answer be fractional?
- 9 years agoHelpfull: Yes(0) No(0)
- Would b always even...
- 9 years agoHelpfull: Yes(0) No(0)
- odd*odd=odd, odd+odd=even, even+even=even, even*even=even
1/8((odd*odd)+(odd*odd))*(even*even)
=1/8(odd+odd)*even
=1/8even*even
=even
optin (c) is correct - 9 years agoHelpfull: Yes(0) No(1)
- Square of odd digit is always odd
And odd + odd = even
even * even is always even
8 is also even
even*even*even=even
even!=1
1/even=can be fractional - 8 years agoHelpfull: Yes(0) No(1)
- can be fractional becoz let x=1,y=3 and z=2
- 8 years agoHelpfull: Yes(0) No(0)
- Can be even or odd
- 7 years agoHelpfull: Yes(0) No(0)
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