The average atomic mass of a sample of an element \(X\) is 16.2u. What are the percentages of isotopes \(^{16}X_8\) and \(^{18}X_8\) in the sample?
Number of letters
Number of surnames
1 − 4
6
4 − 6
30
6 − 8
44
8 − 12
16
12 − 20
4
(i) Draw a histogram to depict the given information. (ii) Write the class interval in which the maximum number of surnames lie.
Age (in years)
Number of children
1 − 2
5
2 − 3
3
3 − 5
5 − 7
12
7 − 10
9
10 − 15
10
15 − 17
Draw a histogram to represent the data above.
Number of balls
Team A
Team B
1 − 6
2
7 − 12
1
13 − 18
8
19 − 24
25 − 30
31 − 36
37 − 42
43 − 48
49 − 54
55 − 60
Represent the data of both the teams on the same graph by frequency polygons.[Hint: First make the class intervals continuous.]
Which of the following materials fall in the category of a “pure substance”?
(a) Ice(b) Milk(c) Iron (d) Hydrochloric acid (e) Calcium oxide (f) Mercury (g) Brick (h) Wood (i) Air
Simplify : (i) 2 \(\frac{2}{3}\) . 2 \(\frac{1}{5}\) (ii) (\(\frac{1}{33}\))7 (iii) 11 \(\frac{1}{2}\) / 11\(\frac{1}{4}\) (iv) 7 \(\frac{1}{2}\) . 8 \(\frac{1}{2}\)