1. so we are looking for how much her allowance is. Well we know that to get a percentage we just have to do the part over the whole and multiply by 100
so our equation looks like this
(45/x) *100 = 15%
we can change it to
45/x = .15
we need to solve for x. so let get
45 = .15x
45/.15 = x
x = 300
2. You do this by first finding out how much tax there is so
350 * .07 = 24.5
now add that to 35
350 + 24.5 = 374.5
3. So we got figure out how much she marked it up it just like the tax problem but in reverse
26 - 20 = 6
20 * x = 6
where x is the percent we are looking for
x = 6/20
x = .3
so she marked up 30%
