We are given that T = test score, and x = # of hours studied. We are given the same information in numbers:
T = 90
x = 6
y = ?
We need to figure out y in terms of k. Let's set up what we know:
![T = (x)/(ky)](https://img.qammunity.org/2019/formulas/mathematics/high-school/hfbqk6o59xmfrh654eztb4lz7wlcx3bn86.png)
![90=(6)/(ky)](https://img.qammunity.org/2019/formulas/mathematics/high-school/5w3cv83s9mwqc4gwd3t506yc2durotb8af.png)
Let's multiply both sides by y to get rid of it on the right side:
![90y = (6)/(k)](https://img.qammunity.org/2019/formulas/mathematics/high-school/1bgbage4fh11bl6nz8ho787179u48toepk.png)
Now, let's divide by 90 on both sides to get rid of it from the left side (and solve for y):
![y = (6)/(90k)](https://img.qammunity.org/2019/formulas/mathematics/high-school/p9jnjjk7864knoekabavkr9fcfphlhhl14.png)
Your answer is A! If any part didn't make sense, you know where to reach me.