SOLUTION: out of 35 programmers,25 knows FORTRAN, 28 knows pascal and 2 know neither. How many know both the languages?

Algebra ->  Probability-and-statistics -> SOLUTION: out of 35 programmers,25 knows FORTRAN, 28 knows pascal and 2 know neither. How many know both the languages?      Log On


   



Question 173938: out of 35 programmers,25 knows FORTRAN, 28 knows pascal and 2 know neither. How many know both the languages?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Since the combined total of those who either know
fortran or pascal is 25+%2B+28+=+53 is greater than
the total number of programmers, there must be some
who know both. there are 2 who know neither
The total of those who know 1 or both languages is
therefore 35+-+2+=+33
Call the overlap of those who know both x
25 fortran programmers include the overlap
28 Pascal programmers include the overlap also, so
I must subtract x from 28
25+%2B+28+-+x+%2B+2+=+35
55+-+x+=+35
x+=+20
Twenty know both languages