Ihave 3 questions needed! ! you can get 25 points! me! !
1) chole spent 15% of her allowance this month on bread. if she spent $45 on the bread, what was the total allowance?
2) a table cost $350. there is also a sales tax of 7%. how much does the table costs including the sales tax?
3) joey bought a vintage t-shirt for $20. then she turned around and sold it on ebay for $26. what was the percent increase in the price of the shirt?

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%