Using average to calculate half

Question

If 1 kid can eat 5 candies, 2 kids can eat 11 candies and 3 kids can eat 25 candies, then how much can 2.5 kids eat?

I was thinking you calculate the average then use that but I cant just use the average right? I was thinking the average was equal to 2 kids and then add the .5 but that doesn't seem right.

Answer 1

Depends on what mean you are aiming for, arithmetic, geometric, harmonic, etc. In this case, I'd suggest arithmetic mean. So, we have 6 kids, eating 41 candies. So the arithmetic mean ( average), any one kid ate, is $${41\over 6}=6+{5\over 6}$$ candies per child. This makes: $$(6+{5\over 6})\cdot (2+{1\over 2})= 12+3+(1+{4\over 6})+{5\over 12}= 17 +{2\over 12} $$ candies for two and a half children.

Of course It depends on how you interpret the question. The ambiguous word is can

Answer 2

I think this approach might be the right one. Let me know. $$n_{candies}=\frac{1}{2.5}\times\biggl(\frac{5}{1}+\frac{11}{2}+\frac{25}{3}\biggr)=\frac{30+33+50}{2.5\times6}=\frac{113}{15}=7.533333333333333$$