Question

Match the following columns:

Column I	Column II
(a) The mean of first 10 odd number =	(p) 11.2
(b) The mean of first 10 even numbers =	(q) 10
(c) The mean of first 10 prime numbers =	(r) 11
(d) The mean of first 10 composite numbers =	(s) 12.9

(a) .......,
(b) .......,
(c) .......,
(d) .......,

Answer 1

$\mathrm{Mean}=\frac{\mathrm{Sum}\mathrm{of}\mathrm{all}\mathrm{observations}}{\mathrm{Total}\mathrm{number}\mathrm{of}\mathrm{observations}}$

(a) The first 10 odd numbers are 1, 3, 5, 7, 9, 11, 13, 15, 17 and 19.

$\mathrm{Mean}=\frac{1+3+5+7+9+11+13+15+17+19}{10}=\frac{100}{10}=10$

(b) The first 10 even numbers are 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20.

$\mathrm{Mean}=\frac{2+4+6+8+10+12+14+16+18+20}{10}=\frac{110}{10}=11$

(c) The first 10 prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23 and 29.

$\mathrm{Mean}=\frac{2+3+5+7+11+13+17+19+23+29}{10}=\frac{129}{10}=12.9$

(d) The first 10 composite numbers are 4, 6, 8, 9, 10, 12, 14, 15, 16 and 18.

$\mathrm{Mean}=\frac{4+6+8+9+10+12+14+15+16+18}{10}=\frac{112}{10}=11.2$

Hence, the correct answers are:

$$\begin{gathered} \left(\mathrm{a}\right)\leftrightarrow \left(\mathrm{q}\right) \\ \left(\mathrm{b}\right)\leftrightarrow \left(\mathrm{r}\right) \\ \left(\mathrm{c}\right)\leftrightarrow \left(\mathrm{s}\right) \\ \left(\mathrm{d}\right)\leftrightarrow \left(\mathrm{p}\right) \end{gathered}$$