Question

Find the discrete variable
(a) Number of chocolates in the box
(b) Time is taken by an athlete
(c) Height of a student in the class
(d) Weight of animals in the zoo

Answer 1

Hint: To solve this question, firstly we will see what is the main difference between a continuous variable and a discrete variable. After that, we will analyze every four options and will discard the wrong answer on the basis of fact, and will choose the right answer.

Complete step-by-step solution:
Before we solve this question, let us see what are variables and what are types of variables.
Variables are the unspecified term of the equation, formula, or theory. It is basically a numeric unspecified number.
A variable may be continuous or discrete. If a variable can take two particular real values such that it can also take on all real values between them, the variable is continuous in that interval whereas discrete variables are countable in a finite amount of time.
Now, let us analyze the options one by one.
Now, in a box the number of chocolates will be the same for any number of times without any change, so we can count the chocolates easily. Hence, it is a discrete variable.
Now, in a race, an athlete can improve the time taken to complete a race. So, there is no fixed time, which can be calculated for an athlete to complete a race. Hence, it is not a discrete variable.
Now, the height of a student keeps on increasing by time. So, there is no fixed height of a student by the passing of time. Hence, it is not a discrete variable.
Now, the weight of any animal in the zoo keeps on increasing or decreasing over time. So, there is no fixed weight of animals in the zoo by the passing of time. Hence, it is not a discrete variable.
Hence, option ( a ) is true.

Note: To solve such questions, try to figure out the wrong answer on the basis of the definition of a continuous variable and discrete variable. Always remember that discrete variables are countable in a finite amount of time. Here logic will work for discarding the option.