Question

how

much pure alcohol must be added to 400 mL of a 15% solution to make i​ts strength 32%

Answer 1

Answer:

Step-by-step explanation:

100ML of alcohol should be added

Answer 2

$quantity \: of \: alcohol \: in \: 400 \: ml \: solution = \frac{15}{100} \times 400 = 60 \: ml$

let x of alcohol be added

then we have.

$\frac{60 + x}{400 + x} = \frac{32}{100}$

6800+100x=12800+32x.

68x=6800 ml

x=100 ml