Alligation question from Canada
(Canada)
How many grams of sulfathiazole should be added to
3400 g of a 10% sulfathiazole cream to prepare a cream containing 15% sulfathiazole? The answer key says 200 g and I've tried it every way I can think of and cannot get this answer of 200 g.
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Reply
(by Keith)
An Alligation can work like this:
1) Play some tic-tac-toe
100 - - - 5 parts
- - - 15 -
10 - - - - 85 parts
2)Reduce your parts to:
1 part (100%) to 17 parts (10%)
3)Divide your initial volume (10%) by it's # of parts.
3400 ÷ 17 = 200
4)Multiply that amt by the other strengths # of parts.
200 X 1 = 200
But... I'm actually a bigger fan of using an
:
3400(.10)+(X)(1.0)=(3400+X)(.15)
340 + X = 510 + .15X
.85X = 170
X = 200
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