ok. We are given the following equation:

Where:

Since we are asked to determine "H" we will solve for "H" in the equation. To do that we will first multiply both sides by -1:

Now, we will use the following property of logarithms:

Applying the property and having into account that:

We get:

Now we substitute the given value of "pH = 4.5":

Solving the operation:

Therefore, the hydrogen ion concentration of the fluid is 0.000032
your calculations for volume (pi x r^2 × h) and surface area (2 × pi × r (h+r)) are correct. However your ratio are incorrect. From the formulas the ratio of surface area to volume would be r×h:2(h+r)
600 people could ride because 60 times 10 is 600 and there is 10 half hours in five hours.
Answer(s):
9 × 11 = 99
11 × 9 = 99
33 × 3 = 99
3 × 33 = 99
1 × 99 = 99
99 × 1 = 99
Decimals:
6 × 16.5 = 99
I hope these helped!