Percentage and Rule Of Three
"Percentage" is the result obtained by multiplying a quantity by a percent, so 10 percent of 50 apples is 5 apples: the 5 apples is the percentage. + Y (5 apples) + P (10%) + X (50 apples)
Basic Formula
X/Y = P*100
Basic Problems
- Find P percent of X
- Find what percent of X is Y
- Find X if P percent of it is Y
Variations
- Y (Percent)
- P (Percentage)
- X (Total)
Y = (P/100) * X
- P percent of X is what? (5% of 29 is 1.45)
- What is P percent of X? (10% of 25 is 2.5)
- What of X is P percent? (2.75 of 25 is 11%)
P = (Y/X) * 100
- Y is what percent of X? (12 is 30% of 40)
- Y of X is what percent? (9 of 13 is 69.23%)
- What percent of X is Y? (22.22% of 27 is 6)
X = Y/(P/100)
- Y is P percent of what? (9 is 60% of 15)
- Y of what is P percent? (4 of 33.3333 is 12%)
- P percent of what is Y? (20% of 35 is 7)
Rule Of Three
It allows you to solve problems based on proportions.
Basic Formula
A/B = C/X
Sources
- Percentage: Edward Furey (Calculator Soup)
- Rule Of Three: Manual do Mundo
Tests
