Question

Your cousin is taking the train to Washington to visit her parents. She has at most $15 to spend on snacks and reading materials. Granola bars cost $1.15 each and magazines cost $1.25. If your cousin buys the same number of granola bars and magazines. how many can she buy? This is an inequality problem.

Answer 1

if she only has $15 to spend we will use the ≤ sign as this will make sure we either spend less or exactly $15. We will assign x to number of snacks and y to number of magazines, so our magazines will be 1.25y and snacks are 1.15x. since we hav two different variables, we need a second equation, if we will get equal of either, that means x=y so now we have

`\left \{ {{x=y} \atop {1.25y+1.15x \leq 15}} \right.`
since x=y, we can replace either x or y in our second equation

`1.25y+1.15y \leq 15`
solve:

`1.25y+1.15y \leq 15`

`2.40y \leq 15`

`y=6.25`
since we cant have .25 of either one, we will say y is 6 and since x=y, that means x is 6 too

Answer 2

they could purchase 6 each. $1.15×6= $6.90
$1.25×6=$7.50.

$7.50+$690=$14.40