The height of the wall is 6 times its width and length of the wall is 7 times its height .if the volume of the wall be 86436 cu.m.its width is  Choose the most appropriate option.
A) 4 m	B) 5 m	C) 6 m	D) 7 m	E) 8 m

Rationale: "explanation : let width = x then , height = 6 x and length = 42 x 42 x ã — 6 x ã — x = 86436 x = 7 answer : d"
Answer: D