Aptitude - Volume and Surface Area - Discussion
Discussion Forum : Volume and Surface Area - General Questions (Q.No. 14)
14.
A large cube is formed from the material obtained by melting three smaller cubes of 3, 4 and 5 cm side. What is the ratio of the total surface areas of the smaller cubes and the large cube?
Answer: Option
Explanation:
Volume of the large cube = (33 + 43 + 53) = 216 cm3.
Let the edge of the large cube be a.
So, a3 = 216 
a = 6 cm.
 Required ratio = |
 |
6 x (32 + 42 + 52) |  |
= | 50 | = 25 : 18. |
| 6 x 62 | 36 |
Discussion:
24 comments Page 3 of 3.
Tarifa said:
5 years ago
Read the question carefully "total surface areas of the smaller cubes" that means the summation of surface areas for all the smaller three cubes. That's why it is 6* (3*3+4*4+5*5).
Anita said:
5 years ago
Here it is asked ratio be surface area, so why we have used volume formula here? Please explain.
(3)
Sonsm said:
5 years ago
Good, Thanks @Tarifa.
Diya said:
4 years ago
How to get the Ratio from 50/36? Please tell me.
(1)
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