What is the least possible product of 5 different integers, each of wh

Question

What is the least possible product of 5 different integers, each of which is between –5 and 5, inclusive?

A. –1600
B. –1450
C. –1200
D. –840
E. –600

AR15J · Answer

Following 5 distinct values will give the least possible product (-5)*5*4*(-4)*(-3) =(-25)*(-16)*(-3) =-1200 Correct answer is C. ------- +1 Kudos if you like the post

vinhthi · Answer

Can you help me explain what the rule behind this solution?

Thanks.

JeffTargetTestPrep · Answer

We want to create the smallest negative number possible. Thus, the smallest product would be:

-5 x 5 x 4 x -4 x -3 = -1200

Answer: C

Dokami · Answer

Honestly, I don't understand this question... 
The Number which we are looking for should be devisible by 5,4,3,2,1 and their negatives.
So, 3*4*5= 60 and 60 is devisible by all of the numbers and their negatives.

Why do we have to calculate this way: (-5)*5*4*(-4)*(-3) ?
And if we do so, why only with (-3) instead of (-5)*5*4*(-4)*(-3)*(3) ?

generis · Answer

Dokami  , this is really a maximize / minimize and number properties question. Think about multiplying, the product, and the number line -- not divisibility.

You wrote, "Why do we have to calculate this way: (-5)*5*4*(-4)*(-3)?"

Because to maximize the magnitude of a number, you choose the greatest factors. I'll get to your second question.

The "least possible product" means the most negative number, a big number with a negative sign.

So we want the number farthest to the left of 0 on the number line.

To make a number with a large magnitude from of a bunch of factors multiplied, it makes sense to choose the biggest factors. Integer factors from which to choose:

-5\leq{x}\leq{5}  OR

_-5__-4__-3__-2__-1__0__1__2__3__4__5

I picked +5 and -5 first. They are the greatest factors, so they will maximize the product.
 
Then I picked the next two factors with greatest magnitude: +4 and -4

Now number properties enter**: do you pick 3, or -3?

With these four numbers, there are two positive numbers, and two negative numbers. Product?
(+)(+)(-)(-) = (+)(+) = (+) Positive.

We need a negative number to make the product negative: an odd number of negative factors makes a product negative.

You don't need to know that number property. These numbers are manageable.
(5 * 4 * -5 * -4) = 20 * 20 = 400, because (-5 * -4) = positive 20.

If you pick 3, you get (20 * 20 * 3) = 1200
Pick -3, and you get (20 * 20 * -3) = -1200

-1200 is the least possible product because it uses the largest factors, and is negative. It's as far from zero to the left as the numbers, multiplied, will get.

**Your second question: "And if we do so, why only with (-3) instead of (-5)*5*4*(-4)*(-3)*(3) "
First, the prompt says only 5 numbers.
Second, the product of your numbers is positive, certainly not the "least possible product"; not the most to the left of 0.

Hope that helps.

Dokami · Answer

Perfect, I got it! Thanks a lot!

GMATinsight · Answer

The value of the product will be minimum when

Sign of the result is negative (if possible)
Absolution value of product is maximum

Integers between -5 and +5 are {-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5}

For maximum Absolute values pick {-5, -4, +5, +4}

For negative sign and maximum absolute value pick negative value with greatest absolute value i.e. {-3}

Product = -5*-4*-3*4*5 = -1200

Answer: Option C

Kinshook · Answer

Asked: What is the least possible product of 5 different integers, each of which is between –5 and 5, inclusive?

Biggest number with a negative sign

(-5)*5*4*(-4)*(-3) = -1200

IMO C

What is the least possible product of 5 different integers, each of wh

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What is the least possible product of 5 different integers, each of wh

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