1.

If P and Q are two sets such that P has 40 elements, P ∪ Q has 60 elements and P ∩ Q has 10 elements, how many elements does Q have?

Answer»

Given: 

n(P) = 40 

n (P ∪ Q) = 60 

n (P ∩ Q) =10 

n(Q) = ? 

We know, 

n (P ∪ Q) = n(P) + n(Q) – n (P ∩ Q) 

Substituting the values we get 

60 = 40+n(Q)–10 

60 = 30+ n(Q) 

n(Q) =30 

∴ Q = has 30 elements.



Discussion

No Comment Found

Related InterviewSolutions