1. A survey was made to find the type of music... If 20 people liked classical music, how many young
people were surveyed?
(Classical is 10%)
Solution:
Let the total number of people surveyed be $x$.
Given, 10% of $x = 20$
$\Rightarrow \frac{10}{100} \times x = 20$
$\Rightarrow x = 20 \times 10 = 200$. Total 200 young people were surveyed.
2. The number of hours for which students... For how many hours did the maximum number of students watch
TV?
Solution:
Looking at the graph (assuming peak is at 4-5 hours), the maximum number of students watched TV for
4 to 5 hours.
3. A bag has 4 red balls and 2 yellow balls... What is probability of getting a red ball?
Solution:
Total balls = $4 + 2 = 6$.
Probability of Red Ball = $\frac{\text{No. of Red Balls}}{\text{Total Balls}} = \frac{4}{6} =
\frac{2}{3}$.
Probability of Yellow Ball = $\frac{2}{6} = \frac{1}{3}$.
Since $\frac{2}{3} > \frac{1}{3}$, getting a Red ball is more likely than getting a
Yellow ball.
4. When a die is thrown, list the outcomes of an event of getting...
Solution:
Outcomes of a die: {1, 2, 3, 4, 5, 6}
(a) Prime numbers: 2, 3, 5
(b) Not a prime number: 1, 4, 6
5. ...Make a frequency distribution table using tally marks.
Solution:
W (Women): |||| |||| |||| |||| |||| |||| (28)
M (Men): |||| |||| |||| | (15)
B (Boys): |||| | (5)
G (Girls): |||| |||| || (12) (Note: Exact count depends on precise tally of the provided string).
Solution:
(i) The group 830-840 has the maximum number of workers (9).
(ii) Workers earning ₹850 or more = $1 + 3 + 1 + 1 + 4 = 10$.
(iii) Workers earning less than ₹850 = $3 + 2 + 1 + 9 + 5 = 20$.
10. Numbers 1 to 10... What is the probability of...
Solution:
Total outcomes = 10.
(i) Getting 6: One outcome (6). P = $1/10$.
(ii) Less than 6: {1,2,3,4,5}. 5 outcomes. P = $5/10 = 1/2$.
(iii) Greater than 6: {7,8,9,10}. 4 outcomes. P = $4/10 = 2/5$.
(iv) 1-digit number: {1..9}. 9 outcomes. P = $9/10$.
SECTION C: CHALLENGERS (5 Marks Each)
11. Explain why a rectangle is called a convex quadrilateral...
Solution:
A rectangle is convex because all its diagonals lie in its interior and all angles are less than
$180^\circ$. A concave polygon has at least one angle greater than $180^\circ$ and some diagonals
lie outside.
Histogram would clearly show bars of height 10, 25, 15, 5.