7.

An agricultural field is in the form of a rectangle having length X1 meters and breadth X2 meters (X1 and X2 are variable). If X1 + X2 = 40 meters, then the area of the agricultural field will not exceed which one of the following values?

UPSC-2016

8.

Let x, y be the volumes, m, n be the masses of two metallic cubes P and Q respectively. Each side of Q is two times that of P and mass of Q is two times that of. P. Let u=m/x and v=n/y. Which one of the following is correct?

UPSC-2020