R S Aggarwal and Veena Aggarwal Solutions for Exercise 1: EXERCISE 19

The table given below shows the ages of $75$ teachers in a school.

Find the probability of teachers who is above $60$ years of age?

The marks obtained by $90$ students of a school in mathematics out of $100$ are given as under:

From these students, a student is chosen at random. What is the probability that the chosen student gets $20\%$ or less marks?

The marks obtained by $90$ students of a school in mathematics out of $100$ are given as:

From these students, a student is chosen at random. If the probability that the chosen student gets $60\%$ or more marks is $\frac{k}{90}$, then find the value of $k$.

It is known that a box of $800$ electric bulbs contains $36$ defective bulbs. One bulb is taken at random out of the box. What is the probability that the bulb chosen is non-defective? Write the answer in a fraction.

Probability of a sure event $=$ _____.

Let $E$ be an event. Then, $P(\mathrm{not} E)=$ _____ $\left[1+P\left(E\right)/1-P\left(E\right)\right]$

$\mathrm{P}\left(\mathrm{E}\right)+\mathrm{P}(\mathrm{not} \mathrm{E})=$ _____.

$0\le P\left(E\right)\le$ _____.