In a class, `30%` of the students offered mathematics, `20%` offered chemistry and `10%` offered both. If a student is selected at random, find the probability that he has offered mathematics or chemistry.

In a class 40% of the students offered Physics 20% offered Chemistry and 5% offered both. If a student is selected at random, find the probability that he has offered Physics or Chemistry only.

In a class,30% of the students offered English,20% offered Hindi and 10% offered both.If a student is selected at random,what is the probability that he has offered English or Hindi? (2)/(5) (b) (3)/(5) (c) (3)/(4) (d) (3)/(10) (e) None of these

In a class 30% of the student fail in Mathematics, 20% of the student fail in English and 10% fail in both. A student is selected at random.

The results of students of a college revealed the following facts. 25% of students failed in Mathematics, 15% of students failed in Chemistry,10% of students failed in both. If a student is selected at random. The probability that he has failed in Mathematics, given that he failed in Chemistry is (i)1/5 (ii)2/3 (iii)3/5 (iv)1/3

In a class 40% students read Mathematics,25% Biology and 15% both Mathematics and Biology.One student is selected at random. The probability that he reads Biology if he reads Mathematics is

In a class 40% students study mathematics 25% study chemistry and 15% both mathematics and chemistry. If a student is chosen at random the probability that he studies mathematics , If it is known that he studies chemistry is