The modal class of the following table will be:
\[ \begin{array}{|c|c|} \hline \text{Class Interval} & \text{Frequency} \\ \hline 0-5 & 5 \\ \hline 5-10 & 8 \\ \hline 10-15 & 12 \\ \hline 15-20 & 10 \\ \hline 20-25 & 7 \\ \hline \end{array} \]
The modal class of the following table will be:
\[ \begin{array}{|c|c|c|c|c|c|} \hline \text{Class Interval} & 0\text{--}5 & 5\text{--}10 & 10\text{--}15 & 15\text{--}20 & 20\text{--}25 \\ \hline \text{Frequency} & 2 & 7 & 11 & 8 & 6 \\ \hline \end{array} \]
Lifetimes (in hours) | 0 - 20 | 20 - 40 | 40 - 60 | 60 - 80 | 80 - 100 | 100 - 120 |
|---|---|---|---|---|---|---|
Frequency | 10 | 35 | 52 | 61 | 28 | 29 |
A student noted the number of cars passing through a spot on a road for 100 periods each of 3 minutes and summarised it in the table given below. Find the mode of the data :
| Number of cars | 0 - 10 | 10 - 20 | 20 - 30 | 30 - 40 | 40 - 50 | 50 - 60 | 60 -70 | 70 - 80 |
| Frequency | 7 | 14 | 13 | 12 | 20 | 11 | 15 | 8 |
The following table shows the ages of tha year:
Age (in years) | 5 - 15 | 15 - 25 | 25 - 35 | 35 - 45 | 45 - 55 | 55 - 65 |
|---|---|---|---|---|---|---|
Number of patients | 6 | 11 | 21 | 23 | 14 | 5 |
Find the mode and the mean of the data given above. Compare and interpret the two measures of central tendency.
(i) Study the diagram and name the parts marked as A, B, C, and D.
(ii) Write the function of A and C.
On the day of her examination, Riya sharpened her pencil from both ends as shown below. 
The diameter of the cylindrical and conical part of the pencil is 4.2 mm. If the height of each conical part is 2.8 mm and the length of the entire pencil is 105.6 mm, find the total surface area of the pencil.