Given that ๐‘Ž and ๐‘ are integers and ๐‘Ž + ๐‘Ž2 ๐‘3 is odd, which one of the following statements is correct

Q. Given that ๐‘Ž and ๐‘ are integers and ๐‘Ž + ๐‘Ž2 ๐‘3 is odd, which one of the following statements is correct?

(A) ๐‘Ž and ๐‘ are both odd(B) ๐‘Ž and ๐‘ are both even
(C) ๐‘Ž is even and ๐‘ is odd(D) ๐‘Ž is odd and ๐‘ is even

Ans: a is odd and b is even

Sol:

Given (a + a2b3) is odd

โ‡’ a (1 + ab3) is odd

As the multiplication of two numbers is odd only when those two numbers are odd.

That means โ€˜aโ€™ is odd and (1 + ab3) is also odd

โ‡’ ab3 is even

As โ€˜aโ€™ is an odd number, b3 should be even number to get ab3 as even.

b3 is even only when b is even.

Therefore, โ€˜aโ€™ is odd and โ€˜bโ€™ is even.

We will be happy to hear your thoughts

Leave a reply

Gkseries.com
Logo
Register New Account