Answer:
9
Step-by-step explanation:
3 times the sum of 4 and 2 = 3*(4+2)
= 3 * 6
= 18
18 - 9 = 9
The best answer to go with is b
I’m pretty sure it would be C
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