Image for booth - size?

i recently got some pictures from a photographer that are to be used for a tradeshow booth (picture to be blown up to 5ft by 5ft)…the images the photographer provided are about 4MB to 6MB (and in the range of 2000-3000 pixels by 2000-3000 pixels and 300 dpi, in JPEG format).

but the company designing the booth says the images need to be in the 100MB area and just the fact that the files are 4MB-6MB in size, tells them resolution is not nearly good enough for a 5ft by 5ft print.

Can anyone please provide some insight into this for me?
I cant imagine 100MB picture files…