There $$3$$ groups of $$5$$ buns in $$15$$ buns: $$15\div 5=3$$, so $$5$$ buns cost $$6\div 3=$$£$$2$$. 
Adam paid £6 for $$15$$ buns. How many dollars did Tom pay for the same kind of buns if he bought $$5$$? 
Options:
1: $$2$$ 
2: $$3$$ 
3: $$4$$ 
4: $$5$$ 