B1. In the country of Mokri breg, an average of $250 \frac{\ell}{\mathrm{m}^{2}}$ of precipitation falls per month. From the graph, it is clear how much precipitation fell in this place each hour on a certain day from 9 to 15 hours.

A. Between which hours did the most precipitation fall?

B. How many liters of rain fell per square meter on that day from 9 to 15 hours?

C. What percentage of the monthly average fell during this time?

D. Aunt Amalija's house has a roof with an area of $150 \mathrm{~m}^{2}$.

![](https://cdn.mathpix.com/cropped/2024_06_07_debf03cdc366cb9b1122g-03.jpg?height=597&width=834&top_left_y=187&top_left_x=1071)

How many cubic meters of rain fell on the roof of her house from 9 to 15 hours on that day?

E. One quarter of the water that flowed off the roof during this time was collected by Aunt Amalija in a reservoir in the shape of a right circular cylinder with a diameter of $2 \mathrm{~m}$. How many centimeters above the bottom of the reservoir was the water level if the reservoir was empty beforehand?
B1. The largest amount of precipitation fell between 12 and 1 PM.

In all six hours, $10 \ell+17 \ell+15 \ell+29 \ell+21 \ell+8 \ell=100 \ell$ of rain fell per $\mathrm{m}^{2}$. In the six hours shown, $100 \frac{\ell}{\mathrm{m}^{2}}$ of rain fell, which accounts for $40 \%$ of the monthly average. On a roof with an area of $150 \mathrm{~m}^{2}$, $150 \cdot 100 \ell=15000 \ell=15 \mathrm{~m}^{3}$ of rain fell. The reservoir fills up with $\frac{1}{4}$ of $15000 \mathrm{dm}^{3}=3750 \mathrm{dm}^{3}$ of water. The water in the reservoir with a diameter of $2 \mathrm{~m}$ or a radius of $1 \mathrm{~m}$ reaches a height of $v=\frac{V}{\pi r^{2}}=\frac{3750 \mathrm{dm}^{3}}{\pi\left(10 \mathrm{dm}^{2}\right.}=(11.9 \pm 0.1) \mathrm{dm}=$ $(119 \pm 1) \mathrm{cm}$.

A. The most rain fell between 12 and 1 PM. ............................................ 1 t

![](https://cdn.mathpix.com/cropped/2024_06_07_debf03cdc366cb9b1122g-11.jpg?height=77&width=1545&top_left_y=784&top_left_x=307)

![](https://cdn.mathpix.com/cropped/2024_06_07_debf03cdc366cb9b1122g-11.jpg?height=80&width=1542&top_left_y=851&top_left_x=311)

![](https://cdn.mathpix.com/cropped/2024_06_07_debf03cdc366cb9b1122g-11.jpg?height=60&width=1556&top_left_y=929&top_left_x=296)

![](https://cdn.mathpix.com/cropped/2024_06_07_debf03cdc366cb9b1122g-11.jpg?height=60&width=1542&top_left_y=998&top_left_x=311)
Calculated height to which the water reaches $(119 \pm 1) \mathrm{cm}$. .......................... $1 \mathbf{t}$