SETS H21

 

In Ntoma district the number of people who speak Kiswahili or Lingala is 410. 200 of them speak Kiswahili and 320 of them speak Lingala. How many speak both languages?

 

solution

 

In most cases, OR stands for union whereas AND/BOTH, stands for intersection.

 

Let Kiswahili=n(K), Lingala= n(L).

 

n(K)= 200 ,

n(L)= 320,

n(KuL) = 410,

n(KnL)=?

 

 

 

n(KuL) = n(K) + n(L) - n(KnL)

 

 

410  =  200 + 320 – n(KnL)

 

 

410  =  520 – n(KnL)

 

 

n(KnL) =  520 – 410

 

 

n(KnL) =  110

 

Hence n(KnL)=110 answer

 

TRY THIS……………..

In Bibanja district the number of people who speak Spanish or German is 210. 170 of them speak Spanish and 180 of them speak German. How many speak both languages?