[tex]\frac{4ml}{15ml}=\frac{xml}{100ml}\\\\cross\ multiply\\\\15x=4\times100\\\\15x=400\ \ \ \ |divide\ both\ sides\ by\ 15\\\\x=\frac{400}{15}\ \ \ \ \ |divide\ a\ numerator\ and\ a\ denominator\ by\ 5\\\\x=\frac{80}{3}\\\\x=26\frac{2}{3}\ (ml)\\\\Answer:26\frac{2}{3}\ ml\ of\ red\ paint.[/tex]