Volume and Surface Area- Aptitude Questions and Answers

View in English View in Hindi

If cost of painting is Rs 12 per sq meter of surface area, how much will it cost to paint all surfaces of a solid right circular cylinder with height of 9 meters and base area of 154 sq meters?

A)

Rs. 8448


B)

Rs. 9372


C)

Rs. 1540


D)

Rs. 3180



Correct Answer :

Rs. 8448


Explanation :

Base area of cylinder = πr2 = 154
r2 = 49
Thus, radius, r = 7

Then, Total Surface Area of cylinder = 2πr(h + r) = 2π*7*(9 + 7)
= 2* 22/7 * 7 *(9 + 7)
= 704

Hence, Cost of painting = 12 * 704
= Rs 8448

If the volume of a cylinder is 2156 cubic cm and height is 14 cm, find its radius?

A)

14 cm


B)

21 cm


C)

3.5 cm


D)

7 cm



Correct Answer :

7 cm


Explanation :

h = 14 cm, r = ?
Volume = 2156 cm3
πr2h = 2156
22/7 * r2 *14 = 2156
r2 = 2156*7 / 22*14
r2 = 49
r = 7 cm

Find the curved surface area of a right circular cylinder of height 35 cm and the base radius 6 cm?

A)

1220 cm2


B)

1230 cm2


C)

1320 cm2


D)

1330 cm2



Correct Answer :

1320 cm2


Explanation :

Curved surface area of cylinder= 2πrh
= 2*π*6*35
= 2*(22/7)*6*35 (π = 22/7)
= 1320 cm2

The volume of a cuboid is 3600 m3. If its length is 25 m and its breadth and height are in the ratio 4:1 respectively , then the total surface area of the cuboid is ?

A)

1788 m3


B)

1432 m3


C)

1825 m3


D)

588 m3



Correct Answer :

1788 m3


Explanation :

volume of a cuboid, V = LBH (L=length, B = breadth, H=height).
ratio of breadth and height =3:2, let breadth=4X and height= X.
As given
3600 = 25 * 4X * X
X2 = 36
X = 6
So, breadth=24 height=6

Total Surface Area = 2(LB + BH + HL)
= 2(25*24 + 24*6 + 6*25)
= 12(25*4 + 24 + 25)
= 12(149)
= 1788

A ball of radius 1 cm is put into a cylindrical pipe so that it fits inside the pipe. If the length of the pipe is 14 m, what is the surface area of the pipe?

A)

2200 square cm


B)

4400 square cm


C)

8800 square cm


D)

17600 square cm



Correct Answer :

8800 square cm


Explanation :

Radius of cylinder pipe = 1 cm

Length or height of cylinder pipe = 14 m = 1400 cm

Surface Area of cylinder pipe = 2πrh

Surface area of cylinderpipe = 2 × 22/7 × 1 × 1400

Surface Area = 8800 square cm

If the surface area of a sphere is reduced to one ninth of the area, its radius reduced to ?

A)
One-fourth

B)
One-third

C)
One-fifth

D)

One-ninth



Correct Answer :

One-third


Explanation :

Let original and new radius of the sphere are r and R respectively
Surface Area of Sphere = 4πr2

according to the question
4πr2 = 1/9 (4πR2)
r2 = R2 / 9
r = R / 3

Ice-cream, completely filled in a cylinder of diameter 35 cm and height 32 cm, is to be served by completely filling identical disposable cones of diameter 4 cm and height 7 cm. The maximum number of persons that can be served in this way is?

A)
950

B)
1000

C)
1050

D)

1100



Correct Answer :

1050


Explanation :

Volume of cylinder = πr2h = π * (35/2)2 * 32
Volume of cone = 1/3 πr2h = 1/3 * π (4/2)2 * 7

Number of persons = Volume of cylinder / Volume of cone
=(π * 35/2 * 35/2 * 32) / (1/3 * π * 4/2 * 4/2 * 7)
= 3 * 35 * 35 * 32 / 4 * 4 * 7
= 1050

In a temple there are 25 cylindrical pillars. The radius of each pillar is 28cm and height 4m. The total cost of painting the curved surface area of pillars at the rate of Rs. 8 per m2 is:

A)

Rs. 1408


B)

Rs. 1760


C)

Rs. 1480


D)

Rs. 2520



Correct Answer :

Rs. 1408


Explanation :

Let radius r = 28 cm,
height h = 4 m = 4 x 100 cm = 400 cm

curved surface area of one pillar = 2πrh = 2 x 22/7 x 28 x 400 = 70,400 cm2

Then, curved surface area of 25 pillars = 70400 x 25 = 1760000 cm2
= 1760000/10000 m2 = 176 m2

Now, Cost of 25 cylindrical pillars painting = 176 x 8 = Rs 1408

Latest Updates

Indian Geography

What is the approximate distance between earth and the moon?

Indian History

In which year was the battle of ‘Koregaon Bhima’ fought?

The approach that is very useful in organizing the content in history is.

General Knowledge of India

NITI Aayog stands for _____.

General Knowledge of MP

India’s first Ramayan art museum was established at?

Errors Identification

Read the sentence carefully and choose the option that has an error in it:
The management’s trusted employee was suspected of stealing large sum of money.

Read the sentence carefully and choose the option that has an error in it:
The teacher asked the child to repeat again because he spoke feebly.

Fill in the blank

Fill in the blank with the most appropriate preposition in the given sentence.
Let’s sit _________ the shade of this beautiful tree.

Choose the most appropriate determiner for the given sentence.
________of what he said was very sensible.

Substitution

Choose the option that substitutes the given phrase appropriately.
A work of art made by carving

Correct sentence

Choose the option that best transforms the sentence into its Indirect form:
‘What country do you come from?’ said the police officer.

Alternative Phrase

Choose the option that best explains the highlighted expression:
All human beings have feet of clay.

Fill in the blank

Choose an appropriate modal for the given sentence:
My doctor said that I_____ stop smoking as one of my lungs got infected.

Choose the appropriate prepositions for the given sentence:
My parents have been married ________ forty-nine years, but you can still see the love ________ their eyes.

Choose the appropriate conjunction for the given sentence:
______ it rains, the college will declare the holiday.

Antonyms

Choose the appropriate antonym for the highlighted word in the given sentence.
The family protracted their visit by several days.

Tenses

Choose the appropriate tenses to fill in the blanks in the given sentence:
Please _________ a noise. Ritu __________ to sleep.

Synonyms

Choose the appropriate synonym for the highlighted word in the given sentence.
Does he really expect us to believe such a flimsy excuse?