For Postorder Root will be at rightend.
For Inorder Root will be at Middle.
Now look at the post order where is a(root) last end. find element a in inorder it is somewhere in middle.
Consider inorder , Pull that a in to top now left children will be elements left to a and right children will be elements right to a
Check for next element from right corner in postorder i.e.,d find where is d in inorder pull it to top and repeat the above steps.
Final resultant tree and its preorder.