HELP PLEASE PLEASE HELP

5) Toblerone is a popular chocolate snack that comes in a triangular prism container.
The dimensions of one Toblerone bar is shown on the top right.
If a case of Toblerone as shown on the bottom right is supposed to fit 20 Toblerone bars, what does the minimum volume of the case have to be ?
Triangular Prism
3.5 cm
h
b
SA= bh + 2ls + lb v= 1/2(bl)h
15 cm
0Es80
TOBLERONE
100g
TOBLERON
TOBLERONE
2.4 cm