SAT Math Practice: Linear Functions Practice 01

1. When Billy places a pot of water on the stove for 7 minutes, the temperature of the water is $78 \textdegree F$ . As the pot of the water sits over the stove longer, the temperature increases linearly. After sitting over the stove for 12 minutes, the temperature of the water is $110 \textdegree F$ . If the temperature increase at a constant rate as the time in which the water sits over the stove increases, which of the following linear models best describes the temperature, $t$ , in $\textdegree F$ after a time, $m$ , in minutes sitting over the stove?

$t=6.4m$

$t=6.4m+33.2$

$t=64m+33.2$

$t=-6.4m+33.2$

2. Dr. Bloomfield is a scientist who studies the population of wild animals living in parts of the Atlantic Ocean.After 9 years of scientific studies, he estimates that there are about 3.1 billion animals living in a specific area of the ocean. After 13 years of scientific studies, there are now 2.5 billion animals living in the same area. If the population of animals decreases at a constant rate as the number of years increase, which of the following models best describes the population of animals, $p$ , in millions that are living in the same area of the ocean after $y$ years?