The graph shows the mass, in kilograms, of Jeff's pet Atlantic cod, given its age in years. What is the age of the cod when its mass is $15 \mathrm{~kg}$ ?

![](https://cdn.mathpix.com/cropped/2024_04_20_6ed09463f225f8ba1f07g-062.jpg?height=382&width=894&top_left_y=1473&top_left_x=580)
(A) 3
(B) 7
(C) 4
(D) 6
(E) 5
A mass of $15 \mathrm{~kg}$ is halfway between $10 \mathrm{~kg}$ and $20 \mathrm{~kg}$ on the vertical axis. The point where the graph reaches $15 \mathrm{~kg}$ is halfway between 6 and 8 on the horizontal axis.

Mass of Jeff's Pet Atlantic Cod

![](https://cdn.mathpix.com/cropped/2024_04_20_faa9db06d997f2a5b9b1g-108.jpg?height=320&width=895&top_left_y=1426&top_left_x=672)

Therefore, the cod is 7 years old when its mass is $15 \mathrm{~kg}$.

ANSWER: (B)