Answer: I’ll show you
For ex: 35% of class is dark-haired, 45% of class is fair-haired, rest 6 persons are bald. Count class altogether
1.To get full class you need 100% so you subtract from those percent, and you get percent of bald persons.
100-80 = 20
So 20% of class is bald.
2. Now you know 20% is bald you can count other:
20%-6 |:4(It mean divide both side)
5%-1.5 (6:4 is 1.5, and 20:4 is 5)
3.Now multiply to get 35% and 45%:
5%-1.5 |*7 (5*7=35) (5*9=45)
35% - 10.5 (1.5*7=10.5)
45% - 13.5 (1.5*9=13.5)
So you know now answer:
Those 35% which are dark-haired are 10.5 persons, and 45% is 13.5 person.
4. Now add together scores, to get number of people in class:
13.5+10.5+6=30
Answer: The class has 30 persons.
So thats how you solve proportion.