I need some help on these problems:

1) A swimming pool measures 9.0 m long by 3.5 m wide by 1.75 m deep. What mass of water in metric tons (1 metric ton = 1000 kg) does the pool contain when filled? The density of the water is 0.991 g/cm3.

2) If a liquid has a density of 1.17 g/cm3, how many liters of the liquid have a mass of 3.75 kg?

3) When a sample of a metal alloy that has the mass of 9.65 g is placed into a graduated cylinder containing water, the volume reading in the cylinder increases from 16.0mL to 19.5mL. What is the density of the alloy sample in grams per cubic meter?

Q1. The answer is 54.629 metric tons

A mass (m) of a liquid is its density (D) multiplied by its volume (V): m = D · V
Step 1. Calculate the volume (V) of the swimming pool.
Step 2. Calculate the mass (m) of the water.
Step 3. Convert the mass into the metric tones.

Step 1.
V = w l h (w - weight, l - length, h - height)
w = 3.5 m
l = 9 m
h = 1.75 m
_______
V = 3.5 9 1.75
V = 55.125 m³

Step 2:
m = D V
D = 0.991 g/cm³
1 g = 0.001 kg
1 cm³ = 0.000001 m³
D = 0.991g / 1cm³ = 0.991 0.001 kg / 0.000001 m³ = 991 kg/m³
V = 55.125 m³
_________
m = 991 55.125
m = 54628.875 kg ≈ 54629 kg

Step 3.
Since 1 metric ton is 1000 kg, how many metric tons are 54629 kg?
1 mt : 1000 kg = x : 54629 kg
x = 1 mt : 1000 kg 54629 kg
x = 54.629 metric tons

Q2. The answer is 3.2 l.

Step 1. Convert g/cm³ into kg/dm³ (because 1 l = 1 dm³)
Step 2. Calculate how many liters of the liquid have a mass of 3.75 kg using the proportion

Step 1.
D = 1.17 g/cm3
1 g = 0.001 kg
1 cm³ = 0.001 dm³
D = 1.17 0.001 kg / 0.001 dm³ = 1.17 kg/dm³

Step 2.
If 1.17 kg is in 1 dm³, 3.75 kg are in how many dm³:
1.17 kg : 1 dm³ = 3.75 kg : x
x = 3.75 kg 1 dm³ : 1.17 kg
x = 3.2 dm³
1 dm³ = 1 l
x = 3.2 l

Q3. The answer is 2757140 g/m³

Step 1. Calculate the increased volume and convert units into liters.
Step 2. Calculate the density of the alloy sample and convert units into g/m³

Step 1.
The difference in the volume of the water in cylinder is:
V = 19.5 ml - 16 ml = 3.5 ml
1 ml = 0.001 l
V = 3.5 * 0.001 l = 0.0035 l

Step 2.
A density (D) of an object with mass m and volume V is:
D = m/V

We have:
D = ?
m = 9.65 g
V = 0.0035 l
______
D = 9.65/0.0035 g/l = 2757.14 g/l
1 l = 1 dm³ = 0.001 m³
D = 2757.14 g/0.001 m³ = 2757140 g/m³