Of the 400 candidates who were interviewed for a position at a call center, 200 had a laptop, 140 had a calculator and 280 had a mobile phone. 80 of them had both, a laptop and a calculator, 60 had both, a calculator and a mobile phone and 120 had both, a laptop and mobile phone and 20 had all three. On the basis of above information answer the following questions.
Question 1. How many candidates who attended the interview had at least one of the three gadgets?
Answers
sry the question is too big .xd
Let S= Total number of candidates, A=Number of candidates having Laptop, B= Number of candidates having Calculator, C= Number of candidates having calculator, A∩B=Number of candidates having both, a laptop and a calculator, B∩C=Number of candidates having both , a calculator and a mobile phone, C∩A=Number of candidates having both laptop and mobile phone ,A∩B∩C=Number of candidates having both laptop , mobile phone and calculator.
Step-by-step explanation:
Given n(S)=n(A∪B∪C)= 400, n(A)= 200, n(B)= 140,n(C)=280,n(A∩B)=80, n(B∩C)=60,n(C∩A)=120, n(A∩B∩C)=20.
n(A ∪ B ∪ C) = n(A) + n(B) + n(C) - {n(A ∩ B) + n(B ∩ C) + n(C ∩ A)} + n(A ∩ B ∩ C)
=200+140+280-{80+60+120}+20
=620-260+20
=380
Therefore at least 380 candidates out of 400 who attended the interview has got any of the three gadgets.