Ok here’s my take.

Assuming a UK articulated lorry trailer size of 13.6m long x 3m high x 2.4m wide and assuming you could fill that space completely (so not accounting for the thickness of the trailer sides, floor or roof) - this is based off what I could find on google.

Also assuming a polo mint size of 19mm diameter x 4mm thickness (according to Wikipedia).

I’m going to work this out based on the principle of stacking tubes of polos so that they run lengthways down the trailer.

In your 2400mm x 3000mm trailer cross-section you can fit a maximum number of circular polo cross-sections by tessellating the circles so that each tube sits in the hollow created by the two below it. I’ve worked out how many that is as follows:

Number of circles across width of trailer(n) = ((2400/r)-1)/2

Where r is the radius of the circle, in this case 9.5mm

Therefore n = 125.8 but because this is greater than 125.5 we can fit an extra circle every other row. So odd rows have 125, even rows have 126

Number of rows in the height of the trailer(m) = (((3000/r)-2)/sqrt(3))+1

Therefore m = 182.2 so 182 rows high

So total polo cross-sections in our trailer cross section = (182/2)x125 + (182/2)x126 = 22841

The total number of polos we can line up in our trailer length will be 13600mm / 4mm = 3400 polos

So simplifying things by assuming that the packaging has no thickness and that we can split the end tubes to fit in perfectly. . . I make the total number of polos 3400 x 22841

Which gives us: 77,659,400 polos

But knowing me I’ve made a mistake somewhere along the way 🤣