100 surnames were randomly randomly picked up from a local telephone directory and a frequency distribution of the number of letters in the English alphabet in the surnames was found as follows :

(i) Draw a histogram to depict the given information.

100 surnames were randomly picked up from a local telephone directory and the frequency distribution of the number of letters in the English alphabets in the surnames was obtained as follows: Determine the median number of letters in the surnames. Find the mean number of letters in the surnames? Also, find the model size of the surnames.

Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electronic shells but different in their outermost shells. It was found that elements A and G combine to form an ionic compound which can also be extracted from sea water. Oxides of the elements A and B are basic in nature while those of E and F are acidic. The oxide of elements D is almost neutral. Answer the following questions based on the information given here in : (i) To which group or period of the periodic table do the listed elements belong ? (ii) Which one of the eight elements is likely to be a noble gas? (iii) Which one of the eight elements would have the largest atomic radius ? (iv) Which two elements amongst these are likely to be the non-metals? (v) Which one of these eight elements is likely to be a semi-metal or metalloid ?

The distance (in km) of 40 engineers from their residence to their place of work were found as follows : {:(5,3,10,20,25,11,13,7,12,31),(19,10,12,17,18,11,32,17,16,2),(7,9,7,8,3,5,12,15,18,3),(12,14,2,9,6,15,15,7,6,12):} Construct a grouped frequency distribution table with class size for the data given above taking the first interval as 0-5 (5 not included). What main features do you observe from this tabular representation ?

Thirty children were asked about the number of hours they watched TV programmes in the previous week.The results were found as follows : {:(1",",6",",2",",3",",5",",12",",5",",8",",4",",8),(10",",3",",4",",12",",2",",8",",15",",1",",17",",6),(3",",2",",8",",5",",9",",6",",8",",7",",14",",12):} (i) Make a grouped frequency distribution table for this data 5 and one of the class intervals as 5-10. (ii) How many children watched television for 15 or more hours a weak ?