Question

a submarine was 144 feet below sea level. a shark was hovering at a constant depth above the submarine. the submarine’s depth was twice the depth of the shark. which integer expression describes the position of the shark in relation to sea level? $-144 + 2$ $-144 div 2$ $2(-144)$ $144 div 2$

Explanation:

Step1: Determine submarine's depth

The submarine is 144 feet below sea level, so its depth is represented as $-144$ (negative because it's below sea level).

Step2: Analyze shark's depth relation

The shark is at a constant depth above the submarine, and the submarine’s depth was twice the depth of the shark. Wait, no—wait, re-reading: Wait, the problem says "A submarine was 144 feet below sea level. A shark was hovering at a constant depth above the submarine. The submarine’s depth was twice the depth of the shark." Wait, no, maybe misread. Wait, let's parse again: "A submarine was 144 feet below sea level. A shark was hovering at a constant depth above the submarine. The submarine’s depth was twice the depth of the shark." Wait, so if submarine's depth (below sea level) is twice the shark's depth (below sea level? No, shark is above submarine. Wait, maybe: Let $d$ be shark's depth below sea level. Then submarine's depth is $2d$. But submarine is 144 feet below, so $2d = 144$? No, that can't be. Wait, no, maybe the shark is above the submarine, so shark's depth is less than submarine's. Wait, the problem says "the submarine’s depth was twice the depth of the shark". So submarine depth (below sea level) = 2 * shark depth (below sea level). But submarine is 144 below, so $144 = 2d$ → $d = 72$? But that's not matching options. Wait, maybe I misread the problem. Wait, the options: Let's check the options again. Wait, the original problem: "A submarine was 144 feet below sea level. A shark was hovering at a constant depth above the submarine. The submarine’s depth was twice the depth of the shark. Which integer expression describes the position of the shark in relation to sea level?" Wait, maybe the shark's depth (distance from sea level) is such that submarine's depth (144 below) is twice the shark's depth (so shark is 144/2 = 72 below? No, but shark is above submarine. Wait, no—if submarine is 144 below, and shark is above submarine, and submarine's depth (below) is twice the shark's depth (below). So shark is at depth $x$ below, submarine at $2x = 144$ → $x = 72$. But 72 below is $-72$, but options don't have that. Wait, maybe the problem was "the shark’s depth was twice the submarine’s depth"? No, the text says "The submarine’s depth was twice the depth of the shark." Wait, maybe the options are: Let's list the options:

1. $-144 + 2$
2. $-144 \div 2$
3. $2(-144)$
4. $144 \div 2$

Wait, maybe I misread the problem. Let's re-express: Sea level is 0. Submarine is at $-144$ (144 below). Shark is above the submarine, and submarine's depth (distance from sea level, which is 144) is twice the shark's depth (distance from sea level). So submarine's depth: 144 = 2 * (shark's depth). So shark's depth is 144 / 2 = 72. But since shark is above submarine (which is at -144), shark's position is $-144 + (144 - 72)$? No, that's not. Wait, maybe the shark's depth (below sea level) is half of submarine's. So submarine is at -144, shark is at -144 + (144 - 72)? No, this is confusing. Wait, the options: Let's see the options. The submarine is at -144. The shark is above the submarine, and submarine's depth (144) is twice the shark's depth. So shark's depth (distance below sea level) is 144 / 2 = 72. So shark's position is -72? But how to get that from options. Wait, -144 divided by 2 is -72. So the expression for shark's position is $-144 \div 2$. Let's check the options: option 2 is $-144 \div 2$, which is -72, which would be 72 feet below sea level? Wait, no—if submarine is 144 below, and shark is above, then shark should be less below, so -72 is 72 below, which is above -144 (since -72 > -144). Yes, that makes sense. So the shark's position is $-144 \div 2$.

Answer:

$\boldsymbol{-144 \div 2}$ (corresponding to the second option, e.g., if options are labeled as 1. -144 + 2, 2. -144 ÷ 2, 3. 2(-144), 4. 144 ÷ 2, then the answer is 2. $-144 \div 2$)