English Medium इयत्ता ९ - CBSE Question Bank Solutions

Find the surface area of a sphere of diameter 21 cm.

`["Assume "pi=22/7]`

Find the surface area of a sphere of diameter 3.5 m.

`["Assume "pi=22/7]`

Find the total surface area of a hemisphere of radius 10 cm. [Use π = 3.14]

The radius of a spherical balloon increases from 7 cm to 14 cm as air is being pumped into it. Find the ratio of surface areas of the balloon in the two cases.

A hemispherical bowl made of brass has inner diameter 10.5 cm. Find the cost of tin-plating it on the inside at the rate of ₹ 16 per 100 cm².

`["Assume "pi=22/7]`

Find the radius of a sphere whose surface area is 154 cm².

`["Assume "pi=22/7]`

The diameter of the moon is approximately one-fourth of the diameter of the earth. Find the ratio of their surface area.

A hemispherical bowl is made of steel, 0.25 cm thick. The inner radius of the bowl is 5 cm. Find the outer curved surface area of the bowl.

`["Assume "pi = 22/7]`

A right circular cylinder just encloses a sphere of radius r (see figure). Find

1. surface area of the sphere,
2. curved surface area of the cylinder,
3. ratio of the areas obtained in (i) and (ii).

A survey conducted by an organisation for the cause of illness and death among the women between the ages 15 - 44 (in years) worldwide, found the following figures (in %):-

1. Represent the information given above graphically.
2. Which condition is the major cause of women’s ill health and death worldwide?
3. Try to find out, with the help of your teacher, any two factors which play a major role in the cause in (ii) above being the major cause.

The following data on the number of girls (to the nearest ten) per thousand boys in different sections of Indian society is given below.

1. Represent the information above by a bar graph.
2. In the classroom discuss what conclusions can be arrived at from the graph.

Given below are the seats won by different political parties in the polling outcome of a state assembly elections:-

1. Draw a bar graph to represent the polling results.
2. Which political party won the maximum number of seats?

The length of 40 leaves of a plant are measured correct to one millimetre, and the obtained data is represented in the following table:-

1. Draw a histogram to represent the given data. [Hint: First make the class intervals continuous]
2. Is there any other suitable graphical representation for the same data?
3. Is it correct to conclude that the maximum number of leaves are 153 mm long? Why?

The following table gives the life times of 400 neon lamps:-

1. Represent the given information with the help of a histogram.
2. How many lamps have a life time of more than 700 hours?

The following table gives the distribution of students of two sections according to the mark obtained by them:-

Represent the marks of the students of both the sections on the same graph by two frequency polygons. From the two polygons compare the performance of the two sections.

The runs scored by two teams A and B on the first 60 balls in a cricket match are given below:

Represent the data of both the teams on the same graph by frequency polygons.

[Hint: First make the class intervals continuous.]

A random survey of the number of children of various age groups playing in a park was found as follows:

Draw a histogram to represent the data above.

100 surnames were 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:

1. Draw a histogram to depict the given information.
2. Write the class interval in which the maximum number of surnames lie.

Represent `sqrt6,` `sqrt7,` `sqrt8` on the number line.

Represent `sqrt3.5,` `sqrt9.4,` `sqrt10.5` on the real number line.