Let N denote the set of all natural numbers. Define two binary relations on N as R 1 = x , y ∈ N × N : 2 x + y = 10 and R 2 = x , y ∈ N × N : x + 2 y = 10 . Then

both R 1 and R 2 are transitive relations

both R 1 and R 2 are symmetric relations

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Which of the following sentences contains a compound predicate?

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Important Questions on Relations and Functions

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Mathematics>Algebra>Relations and Functions>Relations

Suppose that

20

pillars of the same height have been erected along the boundary of circular stadium. If the top of each pillar has been connected by beams with the top of all its non-adjacent pillars, then the total number of beams is:

EASY

Mathematics>Algebra>Relations and Functions>Relations

The Number of ways of choosing

10

objects out of

31

objects of which

10

are identical and the remaining

21

are distinct, is:

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Mathematics>Algebra>Relations and Functions>Relations

Consider a class of

5

girls and

7

boys. The number of different teams consisting of

2

girls and

3

boys that can be formed from this class, if there are two specific boys

A

and

B,

who refuse to be the members of the same team, is:

EASY

Mathematics>Algebra>Relations and Functions>Relations

Let

N

denote the set of all natural numbers. Define two binary relations on

N

R_{1} = \{(x, y) \in N \times N : 2 x + y = 10\}

and

R_{2} = \{(x, y) \in N \times N : x + 2 y = 10\}

. Then

EASY

Mathematics>Algebra>Relations and Functions>Relations

There are

m

men and two women participating in a chess tournament. Each participant plays two games with every other participant. If the number of games played by the men between themselves exceeds the number of games played between the men and the women by

84

, then the value of

m

is :

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Mathematics>Algebra>Relations and Functions>Relations

A committee of

11

member is to be formed from

8

males and

5

females. If

m

is the number of ways the committee is formed with at least

6

males and

n

is the number of ways the committee is formed with at least

3

females, then

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Mathematics>Algebra>Relations and Functions>Relations

The value of

\sum_{r = 1}^{10} r \cdot \frac{{}^{n}C_{r}}{{}^{n}C_{r - 1}}

is equal to

HARD

Mathematics>Algebra>Relations and Functions>Relations

If in a regular polygon the number of diagonals is

54

, then the number of sides of this polygon is:

HARD

Mathematics>Algebra>Relations and Functions>Relations

{\sum_{i = 1}^{20} (\frac{^{20} C_{i - 1}}{^{20} C_{i} +^{20} C_{i - 1}})}^{3} = \frac{k}{21},

then

k

equals

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Mathematics>Algebra>Relations and Functions>Relations

A person throws two fair dice. He wins Rs.

15

for throwing a doublet (same numbers on the two dice), wins Rs

12

when the throw results in the sum of

9

, and loses Rs.

6

for any other outcome on the throw. Then the expected gain/loss (in Rs.) of the person is:

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Mathematics>Algebra>Relations and Functions>Relations

Electrophilic addition reactions proceed in two steps. The first step involves the addition of an electrophile. Name the type of intermediate formed in the first step of the following addition reaction.