
A room is 25 ft
A room is 25 ft long , 20 ft wide and 15 ft tall . Express the volume of the room in cubic metres . [ 1m = 3.281ft]
I sure my answer is wrong but I try
Now we have 25 ft long , 20 ft wide and 15 we must change all this to cubic metres
3.281ft = 1m
25 X 3.281ft
20 X 3.281ft
15 X 3.281ft

1m=3.281ft so
1ft=1/3.281m
hence volume will be
15x20x25 x(1/3.281)^3 m^3

What you can do, is to work out first the volume in cubic feet.
Volume = Length x Breadth x Height.
Volume = 25 x 20 x 15 = 7500
Now, you work with the conversion.
1 m = 3.281 ft
1 m^3 = (3.281)^3 ft^3 = 35.320 ft^3
So, 7500 ft^3 = (7500 / 35.320) * 1 = 212 m^3 (3sf)

You're correct about changing the values but you said you think you're answer is wrong, why don't you try posting it?
it should be along the lines of $\displaystyle \frac{25}{3.281}*\frac{20}{3.281}*\frac{15}{3.281}$