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 surfac

Question

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?<br /><br />
A) 2 : 1 B) 3 : 2 C) 25 : 18 D) 27 : 20​

in progress 0
Natalia 4 weeks 2021-08-18T06:51:05+00:00 2 Answers 0 views 0

Answers ( )

    0
    2021-08-18T06:52:35+00:00

    Answer:

    \huge\underline\bold {Answer:}

    Let x be the edge of the large cube. Then,

     {x}^{3}  =  {3}^{3}  +  {4}^{3}  +  {6}^{3}  \\  =  > x {}^{3}  = 27 + 64 + 125 = 216 \\  =  > x =  \sqrt[3]{216}  = 6 \: cm \\

    Therefore, required ratio = Total surface are of smaller cubes ÷ Surface area of smaller cubes

     = 6( {3}^{2} ) + 6( {4}^{2} ) + 6( {5}^{2} ) \div 6(6 {}^{2} ) \\  =  \frac{6 \times 9 + 6(4 {}^{2})  + 6(5 {}^{2}) }{6(6) {}^{2} }

     =  \frac{6 \times 9 + 6 \times 16 + 6 \times 25}{6 \times 36}  \\   =  \frac{54 + 96 + 150}{216}  \\  =  \frac{300}{216}  \\  =  \frac{300}{216}  =  \frac{25}{18}

    = 25 : 18.

    0
    2021-08-18T06:52:48+00:00

    Answer:

    261

    Step-by-step explanation:

    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? Explanation: Volume of the large cube = (33 + 43 + 53) = 216 cm3.

Leave an answer

Browse
Browse

18:9+8+9*3-7:3-1*13 = ? ( )