If n is a positive integer and r is the remainder when n^2-1 is divided by 8, what is the value of r?
(1) n is odd
(2) n is not divisible by 8
Can someone please break this down for me...
Thank.s
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If n is a positive integer and r is the remainder when n^2-1 is divided by 8, what is the value of r?
(1) n is odd
(2) n is not divisible by 8
(1) plug in the numbers 3 and 5 for n, 3^2 - 1=8 so remainder is 0, use 5 to confirm 5^2 - 1=24, so remainder is 0 again
(2)since odd numbers give you a remainder of 0 try an even number such as 2, 2^2 - 1 =3, so the remainder is 3
number 1 is sufficient because it provides a consistent answer, while number 2 is insufficient due to inconsistencies in the remainders.
(1) n is odd
(2) n is not divisible by 8
(1) plug in the numbers 3 and 5 for n, 3^2 - 1=8 so remainder is 0, use 5 to confirm 5^2 - 1=24, so remainder is 0 again
(2)since odd numbers give you a remainder of 0 try an even number such as 2, 2^2 - 1 =3, so the remainder is 3
number 1 is sufficient because it provides a consistent answer, while number 2 is insufficient due to inconsistencies in the remainders.
