Say we want to determine how many people we can invite to a party for a given budget ($ input). We want one snack and one soda for each person. The snack cost is $1 and the soda cost is $1 per can for $2 total.

Question

Say we want to determine how many people we can invite to a party for a given budget ($ input).  We want one snack and one soda for each person.  The snack cost is $1 and the soda cost is $1 per can for $2 total. 
How many people I can invite (the range) based on the amount of money I can spend (the domain $)?   What does the function tell us for the following budgets (How many people can I invite)  $100?  $126?, and $166?

MathMate · Answer

An example of a similar function is f(x) for the number of bus tickets I can buy for x dollars. If a bus ticket costs $2.50, then
f(x)=x/2.50
f(10)=10/2.50=4, so I can buy 4 bus tickets for $10.

You can proceed in a similar way for the party function.