# The Height of a Rectangular Solid is 5 Times Its Width and Its Length is 8 Times Its Height. If the Volume of the Wall is 102.4 Cm3, Find Its Length. - Mathematics

Sum

The height of a rectangular solid is 5 times its width and its length is 8 times its height. If the volume of the wall is 102.4 cm3, find its length.

#### Solution

Height of rectangular solid = 5 x width
and length = 8 x height = 8 x 5 x width = 40 x width
Volume = 102.4 cm3
Let width = w
Then height = 40w
and height = 5w

therefore "w" xx 40"w" xx 5"w" = 102.4

"w"^3 = 102.4/(40 xx 5) = 0.512

= (0.8)^3

∴ w = 0.8

∴ Length = 40w = 40 xx 0.8 = 32 cm

Concept: Surface Area of a Cuboid
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#### APPEARS IN

Selina Concise Mathematics Class 8 ICSE
Chapter 21 Surface Area, Volume and Capacity
Exercise 21 (C) | Q 6 | Page 241