The areal density \( D \) of a fabric can be calculated using the formula:
\[
D = \left( \text{Ends per cm} \times \text{Tex of warp yarns} + \text{Picks per cm} \times \text{Tex of weft yarns} \right) \times 10
\]
Substituting the given values:
\[
D = \left( 20 \times 30 + 30 \times 25 \right) \times 10 = \left( 600 + 750 \right) \times 10 = 1350 \, \text{g/m}^2
\]
Thus, the areal density of the fabric is \( 1350 \, \text{g/m}^2 \).