(d) \(\frac{25}{4}\)
Let the number of workers = x, wage per employee = Rs y
Then, total wages = Rs xy
Number of workers after increase = 1.25x
Reduced wage per employee = Rs 0.75y
\(\therefore\) Total wages = 1.25x × Rs 0.75y = 0.9375xy
\(\therefore\) Required % decrease = \(\frac{Xy-0.9375Xy}{Xy}\) x 100
= 0.0625 x 100 = 6.25
= \(\frac{25}{4}\)%