Dividing a quantity in a given ratio a:b:c means finding x, y, z such that x:y:z = a:b:c and x+y+z = Total. Formula: x = (a/(a+b+c)) × Total, y = (b/(a+b+c)) × Total, z = (c/(a+b+c)) × Total. Example: Divide 600 in ratio 2:3:5. Sum = 10. x = (2/10)×600 = 120, y = 180, z = 300. Solving: (1) Calculate sum of ratio parts; (2) Divide total by sum; (3) Multiply each ratio part by quotient. Shortcut: Reduce ratio to lowest terms first for easier calculation. Exam tip: Always verify that divided parts sum to original total. Practice with different ratio sizes (2:3, 4:5:6, etc.).