Question

If X { x:x is a prime number which is less than 15 } Y={ y:y is a multiple of 7,7 less than or equal to y less than or equal to 30 }, then find 1.) n (x) and 2.) n(y) and 3.) n( X- Y )

Answer 1

Step-by-step explanation:

Given:-

X ={ x:x is a prime number which is less than 15 } Y={ y:y is a multiple of 7,7 less than or equal to y less than or equal to 30 }

To find:-

Find 1.) n (x) and 2.) n(y) and 3.) n( X- Y )

Solution:-

Given sets are :

X ={ x:x is a prime number which is less than 15 }

X ={x:x is a prime number , x≤15}

X = { 2, 3, 5, 7, 11, 13 }

Number of elements in the set X = 6

n(X) = 6

and

Y={ y:y is a multiple of 7,7 less than or equal to y less than or equal to 30 }

=> Y ={y:y is a multiple of 7,7≤y≤30}

Y ={ 7, 14, 21, 28 }

Number of elements in the set Y = 4

n(Y) = 4

Now

X - Y

=> { 2, 3, 5, 7, 11, 13 } - { 7, 14, 21, 28 }

=> {2, 3, 5, 11, 13 }

X- Y = {2, 3, 5, 11, 13 }

Number of elements in the set X-Y = 5

n(X-Y) = 5

Answer:-

i) n(X) = 6

ii) n(Y) = 4

iii) n(X-Y) = 5

Used formulae:-

• The number of elements in a set is called its cardinal number of the set.

• The number of elements in a set A is denoted by n(A).

• If A and B are the two sets then The difference of two sets A and B is denoted by A-B.

• The set of elements in A only is called the difference of the two sets and it is denoted by A-B.

Answer 2

Answer:

pls mark as brain list. tq