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
Answer: x < 4
Step-by-step explanation: When solving the inequality 3x - 3 < 9, just like an equation our first step is to isolate the <em>x</em> term which is 3x by adding 3 to both sides of the inequality.
On the left, -3 + 3 cancels and we have 3x.
Make sure to bring down the < sign.
On the right, 9 + 3 simplifies to 12.
So we have 3x < 12.
Now, divide both sides of the inequality by 3 to isolate <em>x</em>.
When we do that we get <em>x < 4</em>
So our answer is x < 4.
Answer:
9 oranges per glass
Step-by-step explanation: