Help on some math? (Pre-Algebra-Algebra I)?
I need help and nobody is around to help. I really only need the formula, you don't need to work out the problem. it's preferred that you include only one variable in each.
1)A product is on sale for 30% discount. Maria paid $15.12, including a 8% sales tax. Find the original price of the product.
2) A 15-gallon salt-water solution contains 20% pure salt. how much water should be added to produce the solution to 15% salt? Irrelevant side note: I think the physics is wrong on this one lol)
3) A 200-gram chlorine-water solution contains 40% chlorine. How much water should be added to make a new solution that is only 25% chlorine?
4) There are one-dollar bills and five dollar bills in the piggy bank. It has 54 bills with a total value of $174. How many ones and five are in the bank?
5) John gave three fifths of his money to Joe and gave 40 to to Janet. John had $8 left. How much money did John had to start with?
6) Tom ate one-third of the candies in a box. Roger ate 2/5 of the remaining candies. There were 18 candies left. How many candies were in the box to start with?
- 9 years agoFavorite Answer
1- let C be the cost of the merchandize
they deduct the discount then calculate the tax
15.12 = C-(C* discount rate) + [C-(C* discount rate) ]*[tax rate]
plug in solve for C
gal ...........% of salt.......... final solution % of salt
15 gal ....... (0.20) ............. (15+x) (0.15)
15(0.20) + x(1.0) = (15+x)( 0.15), solve for x
3 is similar to 2
- 9 years ago
1.) 15.12= .3x+.08(15.12)
4.)174=x+5y and 54=x+y