90 decreased by 80% = 18
90 decreased by 80 percent is 18. Step-by-step solution with the formula and worked example.
90 decreased by 80% = 18
decreased by %
Solution: 90 decreased by 80 percent
Decrease = 80% × 90 = 72
Result = 90 − 72 = 18
Result = 90 − 72 = 18
Step-by-step explanation
- Find the decrease: 80% of 90 = 72.
- Subtract it from the original: 90 − 72 = 18.
- Shortcut: multiply by (1 − 80/100) = ×0.2.
Good to know
Shortcut: decreasing by 80% is the same as multiplying by 0.2 (that is 100% − 80%). So 90 × 0.2 = 18 in one step.
Frequently asked questions
90 decreased by 80 percent
90 decreased by 80% = 18.
How is it calculated?
See the step-by-step solution above — it uses the standard percentage formula.
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