Need clarification on math problem

[siddhesh.shirodker]

Question:
a and b are consecutive even integers.

Column A: 8[(a-b)^3]
Column B: 64

My question is , is it necessary to assume that a<b ?

[tommywallach]

Hey Siddhesh,

Where did you find the question? In my experience, they shouldn't do that without clarifying, because no, they would not definitively be in order.

2 and 4 are consecutive even integers, but so are 4 and 2. So there's no way to know which is which. Is that our question? Is it a real question? Because if it's real, then I'm just plain wrong! : )

-t

[siddhesh.shirodker]

Hi Tommy,

I have found this problem in one of the mock test.
They have chosen answer as "D" and they state that either a or b could be 2 or 4.

But, as far as I remember, in any question, whenever they state consecutive even integers, we assume x and (x+2), so this case answer should be "B" and not "D".

Kindly correct if I am wrong.

Hey Siddhesh,

Where did you find the question? In my experience, they shouldn't do that without clarifying, because no, they would not definitively be in order.

2 and 4 are consecutive even integers, but so are 4 and 2. So there's no way to know which is which. Is that our question? Is it a real question? Because if it's real, then I'm just plain wrong! : )

-t

[tommywallach]

Hey Siddhesh,

Yes, you are wrong, but not in the way you think.

If I say x and y are consecutive integers, that means one of them is equal to the other one plus one. But there's no way to know if it's:

x = y + 1

OR

y = x + 1

In either case, x and y would be consecutive integers. There is no implication in the original text that y is larger simply because it comes after x in the construction.

Hope that helps!

-t

[siddhesh.shirodker]

Yes. I got it now. My doubt was exactly the same. Thanks Tommy.

Hey Siddhesh,

Yes, you are wrong, but not in the way you think.

If I say x and y are consecutive integers, that means one of them is equal to the other one plus one. But there's no way to know if it's:

x = y + 1

OR

y = x + 1

In either case, x and y would be consecutive integers. There is no implication in the original text that y is larger simply because it comes after x in the construction.

Hope that helps!

-t

[tommywallach]

Glad to help! : )

-t