Room is 4.2 m long and the flooring boards run lengthways. The flooring joists (supports) are set out at 400mm centres. All flooring boards must join on a joist. The timber merchant supplies flooring boards in the following lengths:-

2.7 m
3.0 m
3.6 m
3.9 m

In what length(s) should the flooring boards be ordered so that there will be no waste?

2 answers

Pls explain working out.
400mm = 0.4m
so which length is a multiple of 0.4 ?