Wetlands - St Kilda (Waikato) Mystery Cache

This is an easy field puzzle cache suitable for Geokids and Geopups.  Let them run around and enjoy the pretty centrepiece of this new Cambridge sub-division.  We spotted swallows and pukekos which have already taken up residence in this man-made wetland. 

The  co-ordinates given are your starting point.  Once there solve these three simple problems:-

1. How many wooden slats cross the path here? ( = A )

2. Time for a sit down nearby.  How many stone seats are there? ( = B )

3. Cross over - but watch out for the Troll! How many upright posts in total?  ( = C )

The final co-ordinates to locate the cache are:

S 037 52.4 ( A + C - 10 )

E 175 29.30 ( B - 3 )

Please carefully replace the cache in its original position.