Question

The class mark of the class $100-120$ is:

• A. $100$
• B. $115$
• C. $110$
• D. $120$

Answer 1

The correct option is C

$110$

Find the class mark of the class

Given that, the class mark of the class $100-120$.

Let a be the upper-class boundary, $a=120$

Let b is the lower class boundary, $b=100$

The formula used to find the classmark $=\frac{a+b}{2}$

The class mark of the class $=\frac{120+100}{2}=\frac{220}{2}$

Therefore, The class mark of the class is $110$.

Therefore, option (c) $110$ is the correct answer.