Combine the two ratios by finding a common basis for the total of Han Boon and Richard.<br><br>
• Han Boon : Richard = 4 : 1, so total HB + R = 5 units<br>
• Andy : (HB + R) = 1 : 3<br>
• So Andy : Total of HB&amp;R = 1 : 3 = 5 : 15 (multiply by 3 so HB+R = 15)<br>
• HB : R = 4 : 1 = 12 : 3 (multiply by 3 to match the new HB+R = 15)<br>
• Now Andy : HB : R = 5 : 12 : 3<br><br>
Final Answer: 5 : 12 : 3