Question 177685
4 liters of 5% solution of poison ivy contains 95% water = .95*4 = 3.8 litres of water.
you want to know how much water must you add to make 3% solution of poison ivy.
a 3% solution of poison ivy would contain 97% water.
let x = amount of water you need to add.
your equation becomes:
(.95 * 4) + x = .97 * (x + 4)
this becomes:
3.8 + x = (.97 * x) + (.97 * 4)
this becomes:
3.8 + x = .97 * x + 3.88
subtract .97 * x from both sides and subtract 3.8 from both sides and the equation becomes:
x - .97*x = 3.88 - 3.8
which becomes:
.03*x = .08
divide both sides by .03 and it becomes:
x = .08/.03 = 2.66666666666667
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you have to add 2.666666666667 liters of water to the original solution.
4 litres + 2.66666666667 = 6.666666666667
your new solution has a total of 6.6666666667 litres.
the amount of poison ivy in this new solution stayed the same (you didn't add any more).
that amound was .05 * 4 = .2 litres of poison ivy.
.2 / 6.6666666666667 = .03 * 100% = 3% poison ivy in the solution making it a 3% solution.
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