Maths-
On a new year day every student of a class sends a card to every other student. The postman delivers 600 cards. The number of students in the class are :
Maths-General
- 25
- 34
- 42
- 52
Answer:The correct answer is: 25
Book A Free Demo
+91 
Grade*
Select Grade
Related Questions to study
maths-
A tangent to the ellipse x2 + 4y2 = 4 meets the ellipse x2 + 2y2 = 6 at P and Q. The angle between the tangents at P and Q of the ellipse x2 + 2y2 = 6 is
A tangent to the ellipse x2 + 4y2 = 4 meets the ellipse x2 + 2y2 = 6 at P and Q. The angle between the tangents at P and Q of the ellipse x2 + 2y2 = 6 is
maths-General
maths-
An ellipse has OB as a semi – minor axis, F, F¢ are its foci and the angle FBF¢ is a right angle. Then the eccentricity of the ellipse is
An ellipse has OB as a semi – minor axis, F, F¢ are its foci and the angle FBF¢ is a right angle. Then the eccentricity of the ellipse is
maths-General
maths-
The equation of the tangents drawn at the ends of the major axis of the ellipse 9x2 + 5y2 – 30y = 0 is
The equation of the tangents drawn at the ends of the major axis of the ellipse 9x2 + 5y2 – 30y = 0 is
maths-General
maths-
For the ellipse 3x2 + 4y2 – 6x + 8y – 5 = 0
For the ellipse 3x2 + 4y2 – 6x + 8y – 5 = 0
maths-General
maths-
If S’ and S are the foci of the ellipse 
and P (x, y) be a point on it, then the value of SP + S’P is
If S’ and S are the foci of the ellipse and P (x, y) be a point on it, then the value of SP + S’P is
maths-General
maths-
The eccentricity of the curve represented by the equation x2 + 2y2 – 2x + 3y + 2 = 0 is
The eccentricity of the curve represented by the equation x2 + 2y2 – 2x + 3y + 2 = 0 is
maths-General
maths-
The foci of the ellipse 25 (x + 1)2 + 9 (y + 2)2 = 225 are
The foci of the ellipse 25 (x + 1)2 + 9 (y + 2)2 = 225 are
maths-General
maths-
The eccentricity of the ellipse 9x2 + 5y2 – 30y = 0 is
The eccentricity of the ellipse 9x2 + 5y2 – 30y = 0 is
maths-General
maths-
The sum of all possible numbers greater than 10,000 formed by using {1,3,5,7,9} is
The sum of all possible numbers greater than 10,000 formed by using {1,3,5,7,9} is
maths-General
maths-
Number of different permutations of the word 'BANANA' is
Number of different permutations of the word 'BANANA' is
maths-General
maths-
The number of one - one functions that can be defined from 
into 
is
The number of one - one functions that can be defined from into is
maths-General
maths-
Four dice are rolled then the number of possible out comes is
Four dice are rolled then the number of possible out comes is
maths-General
maths-
The equation ax2 + 2hxy + by2 + 2gx + 2fy + c = 0 represents an ellipse if
The equation ax2 + 2hxy + by2 + 2gx + 2fy + c = 0 represents an ellipse if
maths-General
maths-
The equation of the ellipse whose focus is (1, -1). directrix x – y – 3 = 0 and eccentricity 
is
The equation of the ellipse whose focus is (1, -1). directrix x – y – 3 = 0 and eccentricity is
maths-General
maths-
The eccentricity of the conic 3x2 + 4y2 = 24 is
The eccentricity of the conic 3x2 + 4y2 = 24 is
maths-General