Lolaergasheva wrote:

What is the area of the rectangular region ?

(1) l + w = 6

(2) d^2 = 20

Area of rectangular region is given by \(l*w\).

Statement 1 gives us,\(l+w=6\), but l and w can take any values, so insufficient

Statement 2 gives us \(d^2 = 20\) . Assuming that d refers to length of diagonal, we have \(d^2 = l^2 + w^2 = 20\). Again l and w can take multiple values, so insufficient.

Combining 1 and 2,

we get \(l+w=6\) ... (1)

and \(l^2 + w^2 = 20\).... (2)

Squaring both sides of (1), we get

so, \(l^2 + w^2 + 2l*w = 36\)

Putting \(l^2 + w^2 = 20\) in above we get \(2l*w = 16\) or \(l*w = 8\)

So, sufficient. Answer C