Ratio Trick : Ratios and Proportions : Ratio Comparison Magic: āĻāύā§āĻĒāĻžāϤ āϤā§āϞāύāĻž āĻā§°āĻž āϏāĻšāĻ āĻā§ā§°āĻŋāĻ
Ratio Comparison Magic : āĻāύā§āĻĒāĻžāϤ āϤā§āϞāύāĻž āĻā§°āĻž āϏāĻšāĻ āĻā§ā§°āĻŋāĻ
Trick / āĻā§ā§°āĻŋāĻ: Multiply cross (diagonal multiplication). Bigger product → bigger ratio. āĻā§āϰāĻ āĻā§āĻŖ āĻā§°āĻāĨ¤ āĻĄāĻžāĻā§° āĻā§āĻĒāĻžāĻĻ → āĻĄāĻžāĻā§° āĻ āύā§āĻĒāĻžāϤāĨ¤
Steps / āϧāĻžāĻĒāϏāĻŽā§āĻš
- Two ratios: a:b and c:d // āĻĻā§āĻāĻž āĻ āύā§āĻĒāĻžāϤ āϞāĻāĻ: a:b āĻā§°ā§ c:d
- Multiply cross: a×d and b×cāĻā§āϰāĻ āĻā§āĻŖ āĻā§°āĻ: a×d āĻā§°ā§ b×c
- Compare / āϤā§āϞāύāĻž āĻā§°āĻ:
- If a × d > b × c → a:b is bigger, āϝāĻĻāĻŋ a × d > b × c → a:b āĻĄāĻžāĻā§°
- If a × d < b × c → c:d is bigger, āϝāĻĻāĻŋ a × d < b × c → c:d āĻĄāĻžāĻā§°
- If equal → ratios are equal, āϝāĻĻāĻŋ āϏāĻŽāĻžāύ → āĻ āύā§āĻĒāĻžāϤ āϏāĻŽāĻžāύ
Ex 1: Compare 5:6 and 3:4 // 5:6 āĻā§°ā§ 3:4 āϤā§āϞāύāĻž āĻā§°āĻ
- Cross multiply / āĻā§āϰāĻ āĻā§āĻŖ: 5 × 4 = 20, 3 × 6 = 18
- Compare / āϤā§āϞāύāĻž: 20 > 18 → 5:6 is bigger / 5:6 āĻĄāĻžāĻā§°
Ex 2: Compare 7:9 and 8:11// 7:9 āĻā§°ā§ 8:11 āϤā§āϞāύāĻž āĻā§°āĻ
- Cross multiply / āĻā§āϰāĻ āĻā§āĻŖ: 7 × 11 = 77 , 8 × 9 = 72
- Compare / āϤā§āϞāύāĻž: 77 > 72 → 7:9 is bigger / 7:9 āĻĄāĻžāĻā§°
Ex 3: Compare 2:5 and 3:7 // 2:5 āĻā§°ā§ 3:7 āϤā§āϞāύāĻž āĻā§°āĻ
- Cross multiply / āĻā§āϰāĻ āĻā§āĻŖ: 2 × 7 = 14, 3 × 5 = 15
- Compare / āϤā§āϞāύāĻž: 14 < 15 → 3:7 is bigger / 3:7 āĻĄāĻžāĻā§°
Tips / āĻāĻŋāĻĒāĻ
- Only multiply across diagonals / āĻā§ā§ąāϞ āϤāĻŋā§°ā§āϝāĻ āĻĻāĻŋāĻļā§ āĻā§āĻŖ āĻā§°āĻ
- No need to divide / āĻāĻžāĻ āĻā§°āĻŋāĻŦāϞ⧠āĻĒā§ā§°āϝāĻŧā§āĻāύ āύāĻžāĻ
- Faster than fractions / āĻāĻā§āύāĻžāĻāĻļāϤāĻā§ āĻĻā§ā§°ā§āϤ
Ratio Comparison Tricks
Trick: Cross multiply → Bigger product wins! āĻā§āϰāĻ āĻā§āĻŖ āĻā§°āĻ → āĻĄāĻžāĻā§° āĻā§āĻĒāĻžāĻĻ āĻŦāĻŋāĻāϝāĻŧā§!
Ex 4. Compare: 5:6 and 3:4 // āϤā§āϞāύāĻž āĻā§°āĻ: 5:6 āĻā§°ā§ 3:4
Step / āϧāĻžāĻĒ:
- Cross multiply: 5 × 4 = 20, 3 × 6 = 18
- Compare: 20 > 18
Ans / āĻāϤā§āϤ⧰: 5:6 is bigger / 5:6 āĻĄāĻžāĻā§°
Trick / āĻā§āĻļāϞ: Multiply diagonally; bigger number wins! āĻā§āĻļāϞ: āϤāĻŋā§°ā§āϝāĻ āĻĻāĻŋāĻļā§ āĻā§āĻŖ āĻā§°āĻ; āĻĄāĻžāĻā§° āϏāĻāĻā§āϝāĻž āĻŦāĻŋāĻāϝāĻŧā§āĨ¤
Ex 5. Compare: 7:9 and 8:11 // āϤā§āϞāύāĻž āĻā§°āĻ: 7:9 āĻā§°ā§ 8:11
Step / āϧāĻžāĻĒ:
- Cross multiply: 7 × 11 = 77, 8 × 9 = 72
- Compare: 77 > 72
Ans / āĻāϤā§āϤ⧰: 7:9 is bigger / 7:9 āĻĄāĻžāĻā§°
Trick / āĻā§āĻļāϞ: No need to convert to fraction; just cross multiply. āĻā§āĻļāϞ: āĻāĻā§āύāĻžāĻāĻļāϞ⧠āĻĒā§°āĻŋāĻŦā§°ā§āϤāύ āύāĻā§°āĻŋāĻŦ; āĻā§ā§ąāϞ āĻā§āϰāĻ āĻā§āĻŖ āĻā§°āĻāĨ¤
Ex 6. Compare: 2:5 and 3:7 // āϤā§āϞāύāĻž āĻā§°āĻ: 2:5 āĻā§°ā§ 3:7
Step / āϧāĻžāĻĒ:
- Cross multiply: 2 × 7 = 14, 3 × 5 = 15
- Compare: 14 < 15
Ans / āĻāϤā§āϤ⧰: 3:7 is bigger / 3:7 āĻĄāĻžāĻā§°
Trick / āĻā§āĻļāϞ: Bigger cross product always wins! āĻā§āĻļāϞ: āĻĄāĻžāĻā§° āĻā§āϰāĻ āĻā§āĻĒāĻžāĻĻā§āĻ āĻĄāĻžāĻā§° āĻ āύā§āĻĒāĻžāϤ āĻĻā§āĻā§ā§ąāĻžāϝāĻŧāĨ¤
Ex 7. Compare: 9:10 and 7:8 // āϤā§āϞāύāĻž āĻā§°āĻ: 9:10 āĻā§°ā§ 7:8
Step / āϧāĻžāĻĒ:
- Cross multiply: 9 × 8 = 72, 7 × 10 = 70
- Compare: 72 > 70
Ans / āĻāϤā§āϤ⧰: 9:10 is bigger / 9:10 āĻĄāĻžāĻā§°
Trick / āĻā§āĻļāϞ: Only two multiplications are enough! āĻā§āĻļāϞ: āĻā§ā§ąāϞ ⧍āĻā§ āĻā§āĻŖ āϝāĻĨā§āώā§āĻāĨ¤
Ex 8. Compare: 4:7 and 5:9 // āϤā§āϞāύāĻž āĻā§°āĻ: 4:7 āĻā§°ā§ 5:9
Step / āϧāĻžāĻĒ:
- Cross multiply: 4 × 9 = 36, 5 × 7 = 35
- Compare: 36 > 35
Ans / āĻāϤā§āϤ⧰: 4:7 is bigger / 4:7 āĻĄāĻžāĻā§°
Trick / āĻā§āĻļāϞ: Faster than converting ratios to fractions! āĻā§āĻļāϞ: āĻ āύā§āĻĒāĻžāϤ āĻāĻā§āύāĻžāĻāĻļāϞ⧠⧰ā§āĻĒāĻžāύā§āϤ⧰ āĻā§°āĻžā§° āϤā§āϞāύāĻžāϤ āĻāĻāĻā§ āĻĻā§ā§°ā§āϤāĨ¤
Shortcut / āĻāĻŽā§ āĻĒāĻĨ:
- Always multiply diagonally (cross)
- Bigger product → bigger ratio
- Works every time without fractions
This trick is super handy for exams, speed tests, and competitive problems. āĻāĻ āĻā§āĻļāϞ āĻĒā§°ā§āĻā§āώāĻž, āĻāϤāĻŋ-āĻĒā§°ā§āĻā§āώāĻž āĻā§°ā§ āĻĒā§ā§°āϤāĻŋāϝā§āĻāĻŋāϤāĻžāĻŽā§āϞāĻ āϏāĻŽāϏā§āϝāĻžā§° āĻŦāĻžāĻŦā§ āĻ āϤāĻŋ āĻāĻĒāϝā§āĻā§āĨ¤