The following table gives the life time of 400 neon lamps:
Life time (in hrs.) | 300-400 | 400-500 | 500-600 | 600-700 | 700-800 | 800-900 | 900-1000 |
No. of lamps | 14 | 56 | 60 | 86 | 74 | 62 | 48 |
A bulb is selected at random. Find the probability that the life time of the selected bulb is:
(i) less than 400
(ii) between 300 to 800 hours
(iii)at least 700 hours.
Given,
(i) Probability that the life time of the selected bulb is less than 400 = 
(ii) Probability that the life time of the selected bulb is between 300 – 800 hours = 
(iii) Probability that the life time of the selected bulb is at least 700 hours = 
13