R S Aggarwal Solutions for Exercise 1: EXERCISE

In a class, $40\%$students study mathematics; $25\%$ study biology and $15\%$ study both mathematics and biology. One student is selected at random. Find the probability(in decimals) that he studies mathematics if it is known that he studies biology.

In a class, $40\%$students study mathematics; $25\%$ study biology and $15\%$ study both mathematics and biology. One student is selected at random. If the probability that "he studies biology if it is known that he studies mathematics" is $\frac{3}{k}$, find the value of $k$.

The probability that a student selected at random from a class will pass in Hindi is $\frac{4}{5}$ and the probability that he passes in Hindi and English is $\frac{1}{2}$ What is the probability that he will pass in English if it is known that he has passed in Hindi$?$

The probability that a certain person will buy a shirt is $0.2$, the probability that he will buy a coat is $0.3$ and the probability that he will buy a shirt given that he buys a coat is $0.4$. Find the probability that he will buy both a shirt and a coat.

In a hostel, $60\%$ of the students read Hindi newspaper, $40\%$ read English newspaper and $20\%$ read both Hindi and English newspapers. A student is selected at random. Find the probability that he reads neither Hindi nor English news paper.

(Write answer in fraction form)

In a hostel, $60\%$ of the students read Hindi newspaper, $40\%$ read English newspaper and $20\%$ read both Hindi and English newspapers. A student is selected at random. If he reads Hindi newspaper, what is the probability that he reads English newspaper?

In a hostel, $60\%$ of the students read Hindi newspaper, $40\%$ read English newspaper and $20\%$ read both Hindi and English newspapers. A student is selected at random. If he reads English newspaper, what is the probability that he reads Hindi newspaper?

(Write answer in fraction form)

Two integers are selected at random from integers $1$ through $11$. If the sum is even, find the probability that both the numbers selected are odd.