Question

Let A = {x:x is positive integral multiple of
3 less than 31} and B={x:x is prime
number less than 30 .Then n(AUB)+n(AnB)
is equal to
​

Answer 1

Integral multiples of 3 less than 31 are 3,6,9,12,...30

prime no less than 30: 2,3,5,7,11,13,17,23,29

N(aUB)=10 +9 =19 since bo of elements in a are 10 and in b are 9

So now n (a intersection b)= all common elements in a and b i.e. 3 (1 element)

so n (aub)+n(anb)=19+1=20

PLEASE MARK IT AS BRAINLIEST IF YOU UNDERSTOOD THIS

Answer 2

Answer:

20

Step-by-step explanation:

A=(3,6,9,12,15,18,21,24,27,30)

An= 10

B =(2,3,5,7,11,13,17,19,23,29)

Bn= 10

n(AUB)=An+Bn-n(A inter. B)

n(AUB) = 10+10-1

            =19

also     n(AUB)= An+Bn -n(AՈB)

n(AUB) + n(AՈB) = 19+1=20