The ratings of a three-phase, three-winding transformer are 

Primary: Y connected, $66kV,15MVA$
Secondary: Y connected, 13.2 kV, 10 MVA
Tertiary: $\Delta$ connected, $2.3kV,5MVA$

Neglecting resistances and exciting current, the leakage reactances are:

$$\begin{array}{cc}& X_{PS}=0.09\text{per unit on a}15-MVA,66-kV\text{base}\\ & X_{PT}=0.08\text{per unit on a}15-MVA,66-kV\text{base}\\ & X_{ST}=0.05\text{per unit on a}10-MVA,13.2-kV\text{base}\end{array}$$

Determine the per-unit reactances of the per-phase equivalent circuit using a base of $15MVA$ and $66kV$ for the primary.