Question

The percentage of marks obtained by a student of class X in four unit tests are given below :

Unit test	I	II	III	IV
Marks secured %	62	69	33	86

A test is selected at random. What is the probability that the student gets 69% marks in the test?

Answer 1

Total number of unit tests = 4.

Number of tests in which the student secured 69% marks = 1 (Unit test II).

By formula,

Probability of an event = \[\frac{\text{Number of favourable outcomes}}{\text{Total number of outcomes}}\]

P(student gets 69% marks) = \[\frac{1}{4}.\]

Hence, the required probability = \[\frac{1}{4}.\]