One-fourth of a loaf of bread is "$$1$$ unit". Half a loaf of bread is "$$2$$ units".  One-fourth of a loaf of bread: $$6 \div (2-1) =6$$. A whole loaf of bread: $$6 \times 4 =24$$. 
Half a loaf of bread costs $$6$$ pence more than one-fourth of a loaf of bread. How many pence does a whole loaf of bread cost? ($$1998$$ Math Kangaroo Problem, Level $$3-4$$, Question \#$$14$$) 
1. $$6$$ 
2. $$12$$ 
3. $$18$$ 
4. $$24$$ 
5. $$30$$ 