Home
Class 9
MATHS
80 bulbs are selected at random from a l...

80 bulbs are selected at random from a lot and their life time (in hours) is recorded in the form of a frequency table given below.

Find the probability that bulbs selected randomly from the lot has life less than 900 hours.

Text Solution

Verified by Experts

The correct Answer is:
`9/(16)`
Promotional Banner

Topper's Solved these Questions

  • PROBABILITY

    FULL MARKS|Exercise Assignment (Choose the correct answer)|5 Videos

  • MENSURATION

    FULL MARKS|Exercise Assignment (II. Answer the following questions)|8 Videos

  • REAL NUMBERS

    FULL MARKS|Exercise Text Book Activity (Activity 3:)|1 Videos

Similar Questions

Explore conceptually related problems

Suppose 3 bulbs are selected at random from a lot. Each bulb is tested and classified as defective(N). Write the sample space for the experiment?

In a box there are 20 non-defective and some defective bulbs. If the probability that a bulb selected at random from the box found to be defective is 3//8 then, find the number of defective bulbs.

In a class of 125 students 70 passed in Mathematics, 55 in statistics, and 30 in both. Then find the probability that a student selected at random from the class has passes in only one subject.

A lot of 20 bulbs contain 4 defective ones. One bulb is selected at random from the lot. What is the probability that this bulb is defective? Suppose the bulb selected in previous case is not defective and is not replaced. Now one bulb is selected at random from the rest. What is the probability that this bulb is not defective?

A page is selected at random from a book. The probability that the digit at units place of the page number chosen is less than 7 is

A firm manufactures PVC pipes in three plants viz, X,Y and Z. The daily production volumes from the three firms X,Y and Z are respectively 2000 units, 3000 units and 5000 units. It is known from the past experience that 3% of the output from plant X,4% form plant Y and 2% from plant Z are defective. A pipe is selected at random from a days total production, (i)find the probability that the selected pipe is a defective one (ii)if the selected pipe is a defective ,then what is the probability that it was produced by plant Y?

Coloured balls are distributed in four boxes as shown in the following table. A box is selected at random and then a ball is randomly drawn from the selected box. The colour of the ball is black. What is the probability that ball drawn is from the box III?

A company has two plants to manufacture bicycles. The first plant manufactures 60% of the bicycles and the second plant 40% . 80% of the bicycles are rated of standard quality at the first plant and 90% of standard quality at the second plant. A bicycle is selected random and found to be of standard quality. Find the probability that it comes from the second plant.

Numberse are selected at random, one at a time, from the two-digit numbers 00,01,02,….99 with replacement. An event E occurs if and only if the product of the two digits of a selected number is 18. If four numbers are selected, find probability that the event E occurs at least 3 times.