Radhika ranked 21st from the top and 7th from the bottom in her class. How many students are there in the class?

The correct option is 27.

Step-by-step explanation:

To find the total number of students in the class, we can use the formula for total rank position when an individual's rank is known from both ends (top and bottom):

$\text{Total students}=\left(\text{Rank from the top}\right)+\left(\text{Rank from the bottom}\right)-1$

From the given data:

Radhika's rank from the top = 21
Radhika's rank from the bottom = 7

Since Radhika is counted twice (once from the top and once from the bottom), we subtract 1 from the sum of both ranks:

$\text{Total students}=21+7-1$

$\text{Total students}=28-1=27$

Therefore, there are 27 students in the class.