Request help with the below question, please ans thank you. Also, if you could recommend a video that helps in comprehension of this question, that would also be appreciated. I really want to understand this, but am having a very hard time.

A car dealer selects his cars for sale very carefully so as to ensure the optimization of his profits. He deals in $4$ types of cars A$,$ B$,$ F and G$.$ The purchase value of the cars range at Rs$.60,000,150,000,55,000$ and $220,000$ and the sales value is fixed at Rs$.80,000,175,000,75,000$ and $250,000$ respectively. The probability of sale are $0\mathrm{.}8,0\mathrm{.}9,0\mathrm{.}6$ and $0\mathrm{.}50$ respectively during a period of six months. In order to invest Rs$.20,00,000$ in his deals, he wishes to maintain the rates of purchase of cars as $3$ : $1$ : $2$ : $4.$ Work out how and how much he should buy. Formulate this problem as LP model.