6:18 students in Debra's class own a cellphone. Because there are 24 people in total. Minus the people who already own cellphones. Leaving 18 without cellphones. The ratio is people who have cellphones to people who do not.
24-6=18. Thus, the ratio would be 6:18
3 divided by 1/8 = <em>24 and 0/8</em>
Answer:
68
Step-by-step explanation:
Add all of the numbers together then divide by the amount of numbers there are.
We are given that there are a total of 78 students. If we set the following variables:

Then, the sum of all of these must be 78, that is:

Since there are 15 in chemistry and physics and 47 in chemistry, we may replace that into the equation and we get:

Simplifying:

Now we solve for P by subtracting 62 on both sides:

Therefore, there are 16 students in physics