# CBSE Class 11 Maths Sample Papers

**Marks: 25
Duration: 1 hour**

##### Section A: Each question carries 1 mark

*Question 1*: Give the contrapositive of the following statement: If you eat at Joe’s then you have a credit card.

*Question 2*: For the expression √7+6i find the multiplicative inverse.

*Question 3*: You are given the following compound statement. State its negation: “The absolute value of a real number is positive or negative.”

*Question 4*: Consider that the origin of our co-ordinate gird is being shifted to (-4,-2). If that happens, then find the new co-ordinates of the point (1,-3).

##### Section B: Each question carries 3 marks

*Question 1*: Prove that X ∩ Y = X for the sets X and Y given below:

X={3^n-2n-1,n∈N} and Y={4(n-1),n∈N}

*Question 2*: Given that Cos(x) = 1/7, cos(y) = 13/14 and 0 < x,y < π/2, how would you prove that x-y = π/3?

*Question 3*: The sum of n terms of two different arithmetic progressions are in the ratio: 3n+5 ∶ 5n-9, where n∈N. Then what would be the ratios of the fifth terms of both these arithmetic progressions?

##### Section C: Each question carries 6 marks

*Question 1*: Find a formula for partial sum of the following series:

1 + 3x + 5x^2 + ..... + (2n-3)x^(n-2) + (2n-1)x^(n-1)

*Question 2*: A man standing on top of a 10 meter tree on the banks of a lake sees a kite in the sky above the lake at an angle of elevation of 25 degrees. The reflection of the kite in the lake below as seen by the man makes an angle of depression of 35 degrees. At what height above the surface of the lake is the kite flying?