Question

In Lucille’s class, 35% of the students have blond hair. There are 20 students in the class. How many students have blond hair.

Answer 1

7 students

Explanation:

35% of the students have blond hair, and there are 20 students in the class.

"of" means multiply, therefore multiply 35% and 20.

35%*20

Convert 35% to a decimal by dividing by 100 or moving the decimal place 2 spots to the left.

35/100=0.35

35.0-->3.5-->0.35

0.35*20

Multiply

7

7 students in the class have blond hair.

Answer 2

7 the answer is 7

Explanation:

1. We assume, that the number 20 is 100% - because it's the output value of the task.

2. We assume, that x is the value we are looking for.

3. If 20 is 100%, so we can write it down as 20=100%.

4. We know, that x is 35% of the output value, so we can write it down as x=35%.

5. Now we have two simple equations:

1) 20=100%

2) x=35%

where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that:

20/x=100%/35%

6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for what is 35% of 20

20/x=100/35

(20/x)*x=(100/35)*x -

20=2.85714285714*x -

20/2.85714285714=x

7=x

x=7

now we have:

35% of 20=7

we multiply both sides by x

then we divide both sides by 2.85714285714 to get x