please explain the image

DetsionAbandonmuganete$4$od b$51.$Sitvea o$-2\%$No hingEuhase o$5$Redue OSRachayetuchasePchaseMaugeo$3$Gold $2.$SIlvetAbandonManganese $0-157.$Gold $0-07.$ oI$1$No thJem lad Nate$-$Nbandonl$464$S$-5-0-1$Slve $1020$

Case $2.$

The Metal Discovery Group $($MDG$)$ is a company set up to conduct geological explorations of parcels of land in order to ascertain whether significant metal deposits $($worthy of further commercial exploitation$)$ are present or not. Current MDG has an option to purchase outright a parcel of land for U$ $3$m$.$

If MDG purchases this parcel of land then it will conduct a geological exploration of the land. Past experience indicates that for the type of parcel of land under consideration geological explorations cost approximately U$ $1$m and yield significant metal deposits as follows:

$$ manganese $1\%$ chance

$$ gold $0\mathrm{.}05\%$ chance

$$ silver $0\mathrm{.}2\%$ chance

Only one of these three metals is ever found $($if at all$),$ i$.$e$.$ there is no chance of finding two or more of these metals and no chance of finding any other metal.

If manganese is found then the parcel of land can be sold for U$ $30$m$,$ if gold is found then the parcel of land can be sold for U$ $250$m and if silver is found the parcel of land can be sold for U$ $150$m$.$

MDG can, if they wish, pay U$ $750,000$ for the right to conduct a three$-$day test exploration before deciding whether to purchase the parcel of land or not. Such three$-$day test explorations can only give a preliminary indication of whether significant metal deposits are present or not and past experience indicates that three$-$day test explorations cost U$ $250,000$ and indicate that significant metal deposits are present $50\%$ of the time.

If the three$-$day test exploration indicates significant metal deposits then the chances of finding manganese, gold and silver increase to $3\%,2\%$ and $1\%$ respectively. If the three$-$day test exploration fails to indicate significant metal deposits then the chances of finding manganese, gold and silver decrease to $0\mathrm{.}75\%,0\mathrm{.}04\%$ and $0\mathrm{.}175\%$ respectively.