A student solved for the radius of a circle with a circumference of 12π. In which step did the student make an error?

The student make an error in step 4.

Step-by-step explanation:

Given : A student solved for the radius of a circle with a circumference of 12π.

To find : In which step did the student make an error?

Solution :

Let us write each step to find the radius of a circle from its circumference

Step 1 - Circumference of circle,

Step 2 - Substitute the given circumference,

Step 3 - Divide both sides by 2π,

Step 4 - Solve

, it is incorrect as π  get cancelled

Correct step is  

The radius of the circle is 6 cm.

Step 5 -

Step 6 -  

The student made a mistake in step 4 so step 5 and 6 is automatically invalid.

Therefore, the student make an error in step 4.

answer: 80,000

step-by-step explanation:

the population doubles every day.

10,000*2=20,000 day 4

20,000*2=40,000 day 5

40,000*2=80,000 day 6