Answer:
The probability that a household has at least one of these appliances is 0.95
Step-by-step explanation:
Percentage of households having radios P(R) = 75% = 0.75
Percentage of households having electric irons P(I) = 65% = 0.65
Percentage of households having electric toasters P(T) = 55% = 0.55
Percentage of household having iron and radio P(I∩R) = 50% = 0.5
Percentage of household having radios and toasters P(R∩T) = 40% = 0.40
Percentage of household having iron and toasters P(I∩T) = 30% = 0.30
Percentage of household having all three P(I∩R∩T) = 20% = 0.20
Probability of households having at least one of the appliance can be calculated using the rule:
P(at least one of the three) = P(R) +P(I) + P(T) - P(I∩R) - P(R∩T) - P(I∩T) + P(I∩R∩T)
P(at least one of the three)=0.75 + 0.65 + 0.55 - 0.50 - 0.40 - 0.30 + 0.20 P(at least one of the three) = 0.95
The probability that a household has at least one of these appliances is 0.95