Question

What is the upper class limit for the class $25 - 35$ ?
$(1)$ $25$
$(2)$ $35$
$(3)$ $60$
$(4)$ $30$

Answer 1

We have to find the upper limit of the given class interval $25 - 35$ . We solve this question using the concept of class - marks of the intervals . We should also have the knowledge about the formula for calculating the class mark of the intervals . We should also have the knowledge of the bounds about the intervals of the given interval.

Complete step-by-step solution:
The upper limit of any of the given intervals of the class is the number which is the greater number in the given class interval .
Similarly , the Lower limit of any of the given intervals of the class is the number which is the smaller number in the given class interval .
Given :
In the given interval of the class $25 - 35$ , there are two numbers $25$ and $35$ . Now, when comparing the two numbers one can easily conclude that the number which is greater among the two numbers is $35$ .
Hence , we conclude that the upper class limit of the given class is $35$ .
Thus , the correct option is $(2)$ .

Note: Using the concept of the limits of the intervals of the class , we can also calculate the frequency or the class mark of the given interval . As if we would have to find the class mark of the given interval then we would calculate it using the particular formula as given below :
$class{\text{ }}mark{\text{ }} = {\text{ }}\dfrac{{L.L. + U.L.}}{2}$
Where $L.L.$ is the lower limit of the interval and $U.L.$ is the upper limit of the given interval .
Putting the values of the lower and upper limits in the given formula , we get the value of class mark as :
$class{\text{ }}mark{\text{ }} = {\text{ }}\dfrac{{25 + 35}}{2}$
$class{\text{ }}mark = 30$