Solution to SrImati rAjammA's problem
As I mentioned in my hint, the original motif redrawn on a hexagonal grid, was placed at the centre (in red) and around it six (in dark blue and light blue) more were arranged so that they are all in close contact. Around this second layer, 12 more (in purple and pink) were fit. Six more (in orange) were placed in the fourth layer. We have thus 1+6+12+6 = 25 basic motifs. Actually the fourth layer is not full. There must be 18 in the fourth layer. In the figure on the right side, I filled all the 18 (in orange, red and rose). This is more full without leaving any vacancy. In this there are 1+6+12+18 = 37 basic motifs. If the next layer is similarly filled, there will be 24 in that. The over all basic symmetry is only three-fold. This type of exercise educates one as how to fill motifs and create a lattice with translational symmetry. Crystals are filled with such molecules infinitely along the three directions in three dimensional space. Enjoy!
Regards! - mOhana