Answer:
[tex]5\ liters[/tex]
Step-by-step explanation:
[tex]Sugar\ in\ the\ syrup=40\%\\\\40\%\ of\ 15\ ltrs =\frac{40}{100}\times 15=6\ ltrs\\\\Now\ we\ have\ to\ obtain\ 30\%\ sugar\ syrup. Let\ total\ quantity\ of\ syrup=x\\\\30\%\ of\ x=6\\\\\frac{30}{100}\times x=6\\\\0.3\times x=6\\\\x=\frac{6}{0.3}\\\\x=20\ ltrs\\\\The\ amount\ of\ water\ to\ be\ added =20-15=5\ liters[/tex]
