Set S contains 5 integers, labeled A, B, C, D, and E. If the
sum of all of the elements of set S is odd,
how many of the elements of set S are even? Constraint: A+B+C+D+E=Odd
Asked : Number of even in
S={A,B,C,D,E} ??
(1) The sum of A and B is odd.(A+B)+C+D+E=Odd
(A+B)=odd so either A/B =Even/Odd
(even+odd)+even+odd+odd=odd
S={even,odd,even,odd,odd} or
S={even,odd,odd,odd,even}
Here set has two(2) evens
Or
(even+odd)+even+even+even=odd
S={even,odd,even,even,even}
Here set has four(4) evens
(Not sufficient)
(2) The product of B, C, and D is odd.B•C•D = odd —> odd•odd•odd=odd
A+(B+C+D)+E = odd
Odd+(odd+odd+odd)+odd=odd
S={odd,odd,odd,odd,odd}
The set has no even
Or
Even+(odd+odd+odd)+even=odd
S= {even,odd,odd,odd,even}
Here set has two evens
(1+2) set has two evens in
St.(1) S={
even,odd,odd,odd,
even}
A and E are even and in
St.(2) S={
even,odd,odd,odd,
even}
A and E are even ,
so we are certain that S has two evens which is element A and E
(sufficient)
Tricky one lolx
Hence,C like Carnivores
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