In a statistical investigation of 1003 families of Calcutta, it was found that 63 families has neither a radio nor a TV, 794 families has a radio and 187 has TV. The number of families in that group h

Question

In a statistical investigation of 1003 families of Calcutta, it was found that 63 families has neither a radio nor a TV, 794 families has a radio and 187 has TV. The number of families in that group having both a radio and a TV is

TestHub · Accepted Answer

Given, n ( R ) n ( T ) n ( R ∪ T ) ′ n ( Total ) ⇒ 1003 ⇒ n ( R ∪ T ) ​ = 794 = 187 = 63 = n ( R ∪ T ) + n ( R ∪ T ) ′ = n ( R ∪ T ) + 63 = 940 ​ By set theory ⇒ ⇒ ⇒ ​ n ( R ∪ T ) = n ( R ) + n ( T ) − n ( R ∩ T ) 940 = 794 + 187 − n ( R ∩ T ) n ( R ∩ T ) = 981 − 940 = 41 ​

Mathematics - Sets and Relations Question with Solution | TestHub

Options:

Doubts & Discussion