Question

1500 families were surveyed and following data was recorded about their maids at homes

Type of maids	Only part time	Only full time	Both
Number of families	860	370	250

A family selected at random. Find the probability that the family selected has No maids

Answer 1

Total number of families surveyed = 1500

n(S) = 1500

Number of families used maids = 860 + 370 + 250

= 1480

Number of families not using any maids = 1500 – 1480

= 20

Let E₃ be the event of getting family use no maids

n(E₃) = 20

p(E₃) = `("n"("E"_3))/("n"("S"))`

= `20/1500`

= `2/150`

= `1/75`

Probability of getting no maids = `1/75`