pradeepkaushal9518 wrote:is a^2>3a-b^4?

1.3a-b^4=-5
2.a>5 and b>0

(1) 3a + 5 = b^4
Question reduces to: Is a ^2 > -5? Since a^2 will always be positive so a^2 > 3a-b^4 is true.
Hence (1) is SUFFICIENT.

(2) a > 5 and b > 0 implies if a = 6 and b = 1, a^2 = 36 and 3a-b^4 = 17; here a^2>3a-b^4 is true.
If a = 7 and b = 10, a^2 = 49 and 3a-b^4 = 21 - 10000 = negative value; here also a^2>3a-b^4 is true.
So, (2) is SUFFICIENT.

The correct answer is [spoiler](D)[/spoiler].

pradeepkaushal9518 wrote:thanks rahul . how do u find veritas questions? is they are well enough for gmat level?

You are welcome Pradeep. It would not be appropriate for me to comment on another company's material. However, I would recommend using the OG12 questions as your best practice resource. The OG questions are typically the closest to actual GMAT questions.