Question

two cubes have a volume in ratio 2:1 find the ratio of surface area of another

please answer in the correct way
​

Answer 1

Answer:

Two cubes have their volumes in the ratio 1 : 27. The ratio of their surface areas is

A. 1 : 3

B. 1 : 8

C. 1 : 9

D. 1 : 18

Class 9th

RS Aggarwal & V Aggarwal - Mathematics

13. Volume and Surface Area

Answer

Volume of a cube = (side)3

Volume of a cube = (side)3Let the sides be x and y

Volume of a cube = (side)3Let the sides be x and yRatio of volumes =

Volume of a cube = (side)3Let the sides be x and yRatio of volumes =⇒

Volume of a cube = (side)3Let the sides be x and yRatio of volumes =⇒Surface area of a cube = 6(side)2

Volume of a cube = (side)3Let the sides be x and yRatio of volumes =⇒Surface area of a cube = 6(side)2Ratio of surface areas =

Volume of a cube = (side)3Let the sides be x and yRatio of volumes =⇒Surface area of a cube = 6(side)2Ratio of surface areas == 1: 9

Volume of a cube = (side)3Let the sides be x and yRatio of volumes =⇒Surface area of a cube = 6(side)2Ratio of surface areas == 1: 9

Answer 2

Please mark as brainliest

Answer:

we know that, Volume of cube=a³

Let volume of 1st cube be 2x with side a and other be x with side A (according to given ratio)

Step-by-step explanation:

ATQ: 2x=a³ and, x=A³

a=³√2x and, A=x

we know that, surface area of cube is 6a²

Thus, surface area of 1st cube = 6(³√2x)²

= 6³√4x²

Surface area of 2nd cube=6(x)²=6x²

Ratio of S.A=(6³√4x²)÷(6x²)

Ratio of S.A=³√4:1