Question 1151537
w of the 4%, in ml. of volume
.... TO OBTAIN 600 ML. of 10%...


{{{4w+16(600-w)=10*600}}}

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{{{4w+16*600-16w=10*600}}}

{{{4w-16w=10*600-16*600}}}

{{{16w-4w=16*600-10*600}}}

{{{w(16-4)=600(16-10)}}}

{{{w=600((16-10)/(16-4))}}}

{{{w=600(1/2)}}}

{{{highlight(w=300)}}}

notice that 10% is exactly in the middle between 4% and 16%.