Question

At a DBE lecture of 100 students, there are 29 women and 23 men. Out of these students, 4 are teachers and 24 are either men or teachers. Find the number of women teachers attending the lecture.

Answer 1

We operate the principle of sets to solve the problem. We are given the number of women to be 28 and men to be 23. The intersection will be while the union of both sets will be 24. To calculate the number of women teachers attending the lecture we first sum up the number of women and men and subtract from the intersection of both sets which gives us 3. Therefore, the number of teachers that are men are 3 while the number of women teachers are 1.

Step by step explaination:

Given the following, Let the set for men be represented by MM, that of women be represented by WW and that of teachers represented by TT.

Therefore, number of men i.e n(MM)= 23,

number of women i.e n(WW)= 29

number of teachers i.e n(TT)=4

number of men or teachers i.e n(MM U TT)= 24

Therefore, we have:

n(MM U TT)=n(MM) + n(TT) - n(MM n TT)

Therefore:

n(MM n TT)=n(MM) + n(TT) -n(MM U TT)

n(MM n TT)= 23+ 4 - 24 = 3

There fore number of men that are teachers are n(MM n TT)= 3 .

Therefore, from the number of teachers n(TT)=4

the number of teachers that are men are 3 while the number of women teachers are 1.