1. “Those six trees along the way are all unevenly spaced,” said Doug. Steve nodded. “You may not have noticed, but each of four of the trees is equidistant from two others, and the greatest distance between two adjoining trees is thirty metres.” How were those trees spaced?

5, 10, 25, 15, 30 metres

20, 5, 25, 15, 10 metres

30, 10, 5, 15, 20 metres