What is the volume of the water tank in cubic metres? Three bells ring at intervals of 3 minutes, 6 minutes and 9 minutes respectively. After how long will they ring again together?

Length ($L$) = $24 \, \text{m}$
Width ($W$) = $13 \, \text{m}$
Height ($H$) = $8 \, \text{m}$

The volume of the water tank is $\boxed{2496 \, \text{m}^3}$.

: Three bells ring at intervals of 3 minutes, 6 minutes and 9 minutes respectively. After how long will they ring again together?

3, 6, and 9 minutes.

The bells will ring together again after $\boxed{18 \, \text{minutes}}$.

: A rectangular garden in the shape below was fenced leaving a pathway. Calculate the shaded area.

Outer Length ($L_o$) = $15 \, \text{cm}$
Outer Width ($W_o$) = $13 \, \text{cm}$

Inner Length ($L_i$) = $10 \, \text{cm}$
Inner Width ($W_i$) = $4 \, \text{cm}$

The shaded area is $\boxed{155 \, \text{cm}^2}$.