Given that the width of the sleepers = w, the sleeper spacing = s, then the depth of ballets ‘d’ is
1
\(\frac{{s - w}}{2}\)
2
\(\frac{{s + w}}{2}\)
3
\(s - \frac{w}{2}\)
4
\(w - \frac{s}{2}\)
Given that the width of the sleepers = w, the sleeper spacing = s, then the depth of ballets ‘d’ is