Tuesday, 11 February 2014
In Igowole village the number of people who speak Kiswahili or Kisukuma is 450. 350 of them speak Kiswahili and 300 of them speak Kisukuma. How many speak both languages?
In most cases, OR stands for union whereas AND/BOTH, stands for intersection.
Let Kiswahili=n(K), Kisukuma = n(S).
n(K)= 300 ,
n(KuS) = 450,
n(KuS) = n(K) + n(S) - n(KnS)
450 = 350 + 300 – n(KnS)
450 = 650 – n(KnS)
450 -650 = -n(KnS)
-200 = -n(KnS)
n(KnS) = 200 [after dividing by (-1) on both sides]
Hence n(KnS) = 200 answer
In Mpanda district the number of people who speak French or Kikuyu is 600. 370 of them speak French and 300 of them speak Kikuyu. How many speak both languages?