Questions

$1.$

The following table shows the utility $($measured in dollars$)$ which Lisa derives from water $($in $50$ litre drums$)$ and diamonds $($uncut $1$ carat stones$).$

$\backslash$table$[[$Quantity$,\backslash$table$[[$Water$],[$Total $Utility$]],\backslash$table$[[$Diamonds$],[$Total $Utility$]]],[1,500,150],[2,700,290],[3,800,420],[4,850,520],[5,875,600],[6,885,660]]$

Refer to the above information to answer this question. If the price of both water and diamonds is $$120$ per unit, and Lisa has $$720$ to spend, how many units of each would she purchase?