The area of the region enclosed between pair of the lines $x y=0$ and the lines $x y+5 x-4 y-20=0$, is .............

If three dices are thrown then the probability that the sum of the numbers on their uppermost faces to be atleast 5 is

If $f(x)=3 x+6, g(x)=4 x+k$ and $f \circ g(x)=g \circ f(x)$ then $k=$

If the sum of an infinite GP be 9 and sum of first two terms be 5 then their common ratio is ..........