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

Step-by-step solution

aligned Given, n(R) & =794 n(T) & =187 n(R T)^ & =63 n( Total ) & =n(R T)+n(R T)^ 1003 & =n(R T)+63 n(R T) & =940 aligned By set theory array lc & n(R T)=n(R)+n(T)-n(R T) & 940=794+187-n(R T) & n(R T)=981-940=41 array