In a class, 30% students fail in English, 20% students fail in Hindi and 10% students fail in both English and Hindi. A student is chosen at random, then what is the probability he fail in English, if he has failed in Hindi?

In a college of 30 students fail in physics, 25 fail in mathematics and 10 fail in both. One student is chosen at random. The probability that she fails in physics, if she has failed in mathematics is

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. (a) Find the probability that she reads neither Hindi nor English newspapers. (b) If she reads Hindi newspaper, find the probability that she reads English newspaper (c) If she reads English newspaper, find the probability that she reads Hindi newspaper.

In Class XI of a school 40 % of the students study Mathematies and 30 % study Biology. 10 % of the class study both Mathematics and Biology. If a student is selected at random from the class, find the probability that he will be studying Mathemetics or Biology.

In a group of students , 100 students know Hindi , 50 know English and 25 know both . Each of the students know either Hindi or English . How many students are there in the group ?

The probability that a student will pass the final examinatin in both English and Hindi is 0.5 and the probability of passing neither is 0.1. If the probability of passing the English examination is 0.75. What is the probability of passing the Hindi examination?

Of the students in a college, it is known that 60% reside in hostel and 40% are day scholars (not residing in hostel) . Previous years results report that 30% of all students who reside in hostel attain A grade and 20% of day scholrs attain A grade in their annual examination . At the end of the year, one student is chosen at random from the college and he has an A grade, what is the probability that the student is a hostler ?

In a group of students, 100 students know Hindi, 50 know English and 25 know both. Each of the students knows either Hindi or English. How many students are there in the group?

In a class of 60 students. 30 opted for NCC, 32 opted for NSS and 24 opted for both NCC and NSS. If one of these students is selected at random, find the probability that (i) The student opted for NCC or NSS. (ii) The student has opted neither NCC nor NSS. (iii) The students has opted NSS but not NCC.

In a class of 100 students 60 drinks tea. 50 drink coffee and 30 drink both .A students from this class is selected at random.Find the probability that the student takes (i) atleast one of the two drinks (ii) only one of the two drinks

Out of a group of 200 students (who know at least one language), 100 students know English , 80 students know Kannada, 70 students know . Hindi . If 40 students know all the three languages . Find the number of students who know exactly two languages.