Question

passage ii
urine samples were collected from 4 students on 1 day at 8:00 a.m.
and 8:00 p.m. the samples were then analyzed. tables 1 and 2 show the
volume, color, specific gravity, and the concentration of suspended solids
of the 8:00 a.m. and 8:00 p.m. urine samples, respectively. specific
gravity was calculated as follows:
$$ \text { specific gravity } = \frac { \text { density of sample } } { \text { density of water } } $$
the normal range for the specific gravity of urine is 1.0001 - 1.0350.
one of the 4 students had the flu on the 2 days
preceding the collection of the urine samples
during these 2 days, the student experienced a
net fluid loss due to vomiting and diarrhea. based
on the information provided, the student with the
flu was most likely:
a. student a
b. student b
c. student c
d. student d

Explanation:

To solve this, we analyze the effects of fluid loss (vomiting, diarrhea) on urine:

• Fluid loss causes dehydration, so urine becomes more concentrated (higher specific gravity, higher suspended solids, lower volume, darker color), as the body retains water.
• Compare students:
• Student D: Specific gravity = 1.006 (below normal 1.0001–1.0350? No, 1.006 is within, but wait—wait, fluid loss should increase concentration. Wait, no: normal specific gravity is 1.0001–1.0350. Wait, the student with flu had net fluid loss, so urine should be more concentrated (higher specific gravity, higher suspended solids, lower volume, darker color). Wait, let’s check all:
• Student A: Volume 100 mL (low), Specific gravity 1.028 (high), Suspended solids 74.48 g/L (high), Color 8 (dark).
• Student B: Volume 260 mL (high), SG 1.016 (moderate), Solids 42.56 (moderate), Color 5.
• Student C: Volume 270 mL (high), SG 1.027 (high), Solids 71.82 (high), Color 4.
• Student D: Volume 385 mL (very high), SG 1.006 (low), Solids 15.96 (low), Color 2 (light).

Wait, fluid loss (dehydration) leads to less urine volume (body conserves water), higher specific gravity (more concentrated), higher suspended solids (more solutes per volume), and darker color (more concentrated). So the student with flu should have low volume, high SG, high solids, dark color.

Student A has:

• Volume: 100 mL (lowest of all)
• SG: 1.028 (high, within normal but high relative to others)
• Solids: 74.48 g/L (highest)
• Color: 8 (darkest)

Student D has the opposite (high volume, low SG, low solids, light color)—so D is well-hydrated. Student A shows signs of dehydration (low volume, high concentration), consistent with net fluid loss from flu (vomiting/diarrhea). Wait, but wait—maybe I misread. Wait, the question is which student had the flu (and thus fluid loss). So fluid loss → dehydration → concentrated urine (low volume, high SG, high solids, dark color). Student A fits: lowest volume, highest SG (tied with C? A:1.028, C:1.027), highest solids, darkest color. Student C has higher volume than A. So Student A is most likely. Wait, but let’s recheck:

• Fluid loss → less urine (volume ↓), more concentrated (SG ↑, solids ↑, color ↑).
• Student A: Volume 100 (lowest), SG 1.028 (highest), Solids 74.48 (highest), Color 8 (darkest).
• Student C: Volume 270 (higher than A), SG 1.027 (slightly lower than A), Solids 71.82 (lower than A), Color 4 (lighter than A).
• So A has the most concentrated urine (lowest volume, highest SG, highest solids, darkest color), consistent with net fluid loss from flu.

The student with the flu experienced net fluid loss (vomiting, diarrhea), causing dehydration. Dehydration leads to concentrated urine (low volume, high specific gravity, high suspended solids, dark color). Student A has the lowest urine volume (100 mL), highest specific gravity (1.028), highest suspended solids (74.48 g/L), and darkest color (8), matching the effects of dehydration from fluid loss. Other students (B, C, D) have higher volume, lower concentration, or lighter color, inconsistent with net fluid loss.

Answer:

A. Student A