Question

If n = 1 + x, where x is the product of four consecutive positive integers, then which of the following is true?

I. n is an even number
II. n is a prime number
III. n is a perfect square
IV. n is odd number

पर्याय

• I, III

• I, II

• I, IV

• III, IV

Answer 1

III, IV

Explanation:

We know that product of any two consecutive positive integers is always even number.

So, X = product of any four consecutive positive integers is always even number.

Now, n = (1 + x), is alway a odd number

Let x = 1.2.3.4 = 24

n = 1 + 24 = 25, which is a perfect square

again, for, x = 2.3.4.5 = 120

n = 1 + 120 = 121, a perfect square.

And this will follow for all positive integer value.

Hence, n is a perfect square odd number.