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Compound Percentages

When you need % of %, multiply the decimals or use the shortcut.

When to use

Problems like '80% of 60%' or '30% of 80%'.

Steps

  1. 1.Convert both to decimals or simple fractions
  2. 2.Multiply: 80% x 60% = 0.8 x 0.6
  3. 3.Convert back to percentage

Example: 80% of 60%

Quick method: 8 x 6 = 48 → 48%

Detailed: 0.8 x 0.6 = 0.48 = 48%

Mental approach

Use the digit trick: 8 x 6 = 48, so 80% x 60% = 48%. Works when both are multiples of 10%.

Pen & paper approach

Convert to fractions: 80% = 4/5, 60% = 3/5, multiply: 12/25 = 48%.

Tips

  • •For round 10%-multiples: just multiply the tens digits and add %
  • •30% of 80% = 3 x 8 = 24%
  • •40% of 50% = 4 x 5 = 20%

Try it yourself

70% of 50%

80% of 80%

60% of 40%