Let the observations `x_(i)(1<=i<=10)` satisfy the equations, `sum_(i=1)^(10)(x_(i)-5)=10` then the mean of `x_(i)(1<=i<=10)` is
` a)1`
` b)2`
c) 3
d) 6

Let A B C be a triangle. Let A be the point (1,2),y=x be the perpendicular bisector of A B , and x-2y+1=0 be the angle bisector of /_C . If the equation of B C is given by a x+b y-5=0 , then the value of a+b is (a) 1 (b) 2 (c) 3 (d) 4

If y=3^(x-1)+3^(-x-1) , then the least value of y is (a) 2 (b) 6 (c) 2//3 (d) 3//2

The means of five observations is 4 and their variance is 5.2. If three of these observations are 1,2 and 6, then the other two are (a) 2 and 9 , (b) 3 and 8 , (c) 4 and 7 , (d) 5 and 6

If the curve a y+x^2=7 and x^3=y cut orthogonally at (1,\ 1) , then a is equal to (a) 1 (b) -6 (c) 6 (d) 0

If A=[{:(4,1),(3,2):}] and I=[{:(1,0),(0,1):}] then A^(2)-6A is equal to : a) 3I b) -5I c) 5I d) none of these

A real value of x satisfies the equation (3-4i x)/(3+4i x)=a-i b(a ,\ b in RR),\ if\ a^2+b^2= a. 1 b. -1 c. 2 d. -2

If x=3tant and y=3sect then find (d^2y)/(dx^2) at x=(pi)/(4) (a) 3 (b) (1)/(6sqrt2) (c) 1 (d) (1)/(6)

Let x ,\ y be two variables and x >0,\ \ x y=1 , then minimum value of x+y is (a) 1 (b) 2 (c) 2 1/2 (d) 3 1/3

If x=2+2^(2//3)+2^(1//3) , then the value of x^3-6x^2+6x is (a) 3 b. 2 c. 1 d. -2

Given "^(8)C_(1)x(1-x)^(7)+2*^(8)C_(2)x^(2)(1-x)^(6)+3*^(8)C_(3)x^(3)(1-x)^(5)+...+8*x^(8)=ax+b , then a+b is (a) 4 (b) 6 (c) 8 (d) 10