The initial count of bacteria is `x` and it becomes `y` times every day. The total count of backteria after one week is (a) `7\ x y` (b) `x+7y` (c) `x y^7` (d) `x y^6`

The orthocentre of the triangle formed by the lines x - 7y + 6 = 0, 2x - 5y - 6 = 0 and 7x + y - 8 = 0 is

Add -7x y ,\ -3x y and -9x ydot

The equation of the line passing through the center and bisecting the chord 7x+y-1=0 of the ellipse (x^2)/1+(y^2)/7=1 is (a) x=y (b) 2x=y (c) x=2y (d) x+y=0

If a variable line drawn through the intersection of the lines x/3+y/4=1 and x/4+y/3=1 meets the coordinate axes at A and B, (A !=B), then the locus of the midpoint of AB is (A) 6xy = 7 (x+y) (B) 4 (x+y)^2 - 28(x+y) + 49 =0 (C) 7xy = 6(x+y) (D) 14 (x+y)^2 - 97(x+y) + 168 = 0

If the mean of 6,\ 7,\ x ,\ 8,\ y ,\ 14 is 9, then (a) x+y=21 (b) x+y=19 (c) x-y=19 (d) x-y=21

For nitrogen C_(p)-C_(V)=x and for argon C_(P)-C_(V) =Y. The relation between x and y is given by a) x = y b) x = 7y c) y = 7x d) x = 1/2 y

The point (-4,5) is vertex of a square and one of its diagonal is 7x-y+8=0. The equation of other diagonal is 7x-y+23=0 7y+x+=30 7y+x=31 x-7y=30 x+7y+31=0

One diagonal of a square is along the line 8x-15 y=0 and one of its vertex is (1, 2). Then the equations of the sides of the square passing through this vertex are (a)23 x+7y=9,7x+23 y=53 (b)23 x-7y+9=0,7x+23 y+53=0 (c)23 x-7y-9=0,7x+23 y-53=0 (d)none of these

One diagonal of a square is along the line 8x-15 y=0 and one of its vertex is (1, 2). Then the equations of the sides of the square passing through this vertex are (A) 23 x+7y=9,7x+23 y=53 (B) 23 x-7y+9=0,7x+23 y+53=0 (C) 23 x-7y-9=0,7x+23 y-53=0 (D) none of these

The equation of the ellipse whose focus is (1, -1) , directrix is the line x-y-3=0 and eccentricity is 1/2 , is: (A) 7x^2 + 2xy + 7y^2 + 7 = 0 (B) 7x^2 + 2xy+7y^2 + 10x - 10y - 7 = 0 (C) 7x^2 + 2xy + 7y^2 - 10x + 10y + 7 = 0 (D) none of these