Question

80 bulbs are selected at random from a lot and their lifetime has corded
in the form of a frequency table given below
Lifetime (in hours)
300
500
700
Frequency
10
15
23
25
A bulb is chosen at random from the lot. What is the probability thatth
bulb chosen has lifetime less than 900 hours?​

Answer 1

Answer:

Hint: Probability of an event A, is the ratio of the number of outcomes favourable to the event, to the total number of outcomes. Event is the occurrence/ experiment whose probability has to be found.

P(A) = number of favourable outcomestotal number of outcomesnumber of favourable outcomestotal number of outcomes.

Step-by-step explanation:

Complete step by step solution:

Step 1

Given table:

(SEE THE PICTURE ATTACHED)

Step 2

Number of bulbs with lifetime of 1150 h = 0

Step 3

Total number of bulbs in the lot = 80

Step 4

Probability (one bulb with life time of 1150 h) =number of favourable outcomestotal number of outcomes=number of favourable outcomestotal number of outcomes

=080=080

= 0

Therefore, Probability of one bulb selected at random with lifetime 1150 h is 0.

Note:

Probability of any event is always “greater than and equal to 0” and “less than and equal to 1”.

The set of all possible outcomes is called the sample space, S of the experiment. Any subset E of sample space S is called an event. The probability of event, E is given by:

P(E) = n(E)n(S)n(E)n(S)

Where, n(E)n(E) is the number of elements in set E, n(S)n(S) is the number of elements in the set S.