SOLUTION: You have on hand 800g of 5% coal tar ointment and 1200g of 10% coal tar ointment? How many grams of coal tar should be added to the product to obtain an ointment containing 15% co

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: You have on hand 800g of 5% coal tar ointment and 1200g of 10% coal tar ointment? How many grams of coal tar should be added to the product to obtain an ointment containing 15% co      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 591308: You have on hand 800g of 5% coal tar ointment and 1200g of 10% coal tar ointment?
How many grams of coal tar should be added to the product to obtain an ointment containing 15% coal tar? The right answer 16.5g. But I cannot solve it. I know 100% is mixed.
Found 3 solutions by richwmiller, Hung, Alan3354:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!

800*.05+1200*.1+x=.15*(2000+x)
x=164.7 g


Answer by Hung(2) About Me  (Show Source):
You can put this solution on YOUR website!
How much 30% alcohol, 45% alcohol, 60% alcohol and 95% alcohol could be mixed to make 200ml of 50% alcohol? How do to solve it.
How many milliliters of 28% strong ammonia solution having a specific gravity of 0.89 should be used in preparing 2000ml of 10% ammonia solution with a specific gravity of 0.96? (The right answer 770.5ml of 28% ammonia.) But I cannot solve it. Help to solve them for me.
How many fl oz of phenytoin suspensions containing 25mg/5ml and 10mg/5ml are needed to prepare 250 fl dram of a suspension containing 0.5mg of phenytoin per ml? How do you solve it for me. Please try it?
A vial of cefazolin injection contains 1g in 3ml. If 1.6ml of the injection is diluted to 200ml with sodium chloride injection and if the daily dose is 25mg/kg of body weight, how much of the dilution in milliliters should be administrated daily to child weighing 40lbs? Any people try to solve it for me?

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
You have on hand 800g of 5% coal tar ointment and 1200g of 10% coal tar ointment?
How many grams of coal tar should be added to the product to obtain an ointment containing 15% coal tar? The right answer 16.5g. But I cannot solve it. I know 100% is mixed.
-------------------
If the 5% and the 10% are mixed:
--> 2000 gm of p%
2000*p = 800*5 + 1200*10 = 16000
p = 8%
---------
Add 100% to get some amount of 10%
x*100 + 8*2000 = (x + 2000)*15
100x + 16000 = 15x + 30000
85x = 14000
x =~ 164.7 grams
------------
10 times what you say is the answer ???
==========
The other tutor is just spouting gibberish, tho.