question_answer

A company selected 4000 households at random and surveyed them to find out a relationship between income level and the number of AC sets in their home. The information so obtained, is shown here.

Monthly income (in Rs.)	Number of
	AC/households
	0	1	2	Above 2
<10000	20	80	10	0
10000-14999	10	240	60	0
15000-19999	0	380	120	30
20000-24999	0	520	370	80
25000 and above	0	1100	760	220

Find the probability of households: (a) earning Rs. (15000-19999) per month and having more than one AC. (b) earning Rs. 25000 and more per month  and having exactly one AC. (c) not having any AC.

A)                              

(a)	(b)	(c)
\[\frac{1}{8}\]	\[\frac{11}{40}\]	\[\frac{1}{200}\]

B)

(a)	(b)	(c)
\[\frac{3}{80}\]	\[\frac{17}{40}\]	\[\frac{3}{400}\]

C)

(a)	(b)	(c)
\[\frac{1}{8}\]	\[\frac{17}{40}\]	\[\frac{1}{200}\]

D)

(a)	(b)	(c)
\[\frac{3}{80}\]	\[\frac{11}{40}\]	\[\frac{3}{400}\]

Correct Answer: D

Solution :

Total number of households = 4000 Total number of possible outcomes = 4000 (a) Favourable outcomes = 120 + 30 = 150 Require probability (b) Favourable outcomes = 1100  Required probability (c) Number of households not having any A.C. have monthly income Rs. 10,000 and in the range Rs. Favourable outcomes = 20 +10 = 30  Required probability