Cez005 wrote:
a + b = 8. Is ab > 8?
(1) a2 - b2 = 32
(2) a2 + b2 = 40
A. Statement (1) by itself is sufficient to answer the question, but statement (2) by itself is not.
B. Statement (2) by itself is sufficient to answer the question, but statement (1) by itself is not.
C. Statements (1) and (2) taken together are sufficient to answer the question, even though neither statement by itself is sufficient.
D. Either statement by itself is sufficient to answer the question.
E. Statements (1) and (2) taken together are not sufficient to answer the question.
Kudos if you like the q! Note a2 is equal to a squared and b2 is equal to b squared.
(1) a^2-b^2 = (a+b)(a-b)=32
putting a+b=8----------(x)
we get a-b= 32/8=4-------(y)
solving (x) & (y) we get definite values of a& b
thus we can find value ab
suff
(2) given a+b= 8
sq. both sides
a^2+b^2+2ab=64----(z)
but per option (2) a^2+b^2=40
substituting in eq(z) we get
2ab=64-40=24
thus ab=12
suff
Ans D