A uniform-width boardwalk is built around the inside edge of a rectangular parkland that is 10m by 5m. If the boardwalk takes up 20% of the lot, how wide is the boardwalk to the nearest centimetre?

Question

I have no idea what to do after figuring out that:
Total area= 150m^2
Boardwalk area= 30m^2
Parkland area= 120m^2

Answer 1

Draw a figure. Now look at the area of the boardwalk: 2(Lenght*w ) + 2(Width-2w)w

where w is the width of the boardwarlk, and Lenght, Width is the Lot dimensions, which are given, as is area Length*width>

solve for w