at a supermarket, pineapple juice sells at $1 per pint (16 oz). Greg wants to buy eighteen 40-ounce cans of pineapple juice from the supermarket. How much does he has to pay altogether.

(18 * 40)/ 16 = $_________

To calculate how much Greg needs to pay altogether, we first need to determine the total number of pints of pineapple juice he wants to buy. Since there are 16 ounces in a pint, we can calculate the number of pints in 18 cans of 40-ounce pineapple juice as follows:

Number of pints = (Number of cans) x (Ounces per can) / (Ounces per pint)
Number of pints = 18 x 40 / 16 = 45 pints

Now that we know the number of pints, we can calculate the total cost by multiplying the number of pints by the cost per pint:

Total cost = (Number of pints) x (Cost per pint)
Total cost = 45 x $1 = $45

Therefore, Greg has to pay a total of $45 altogether for the eighteen 40-ounce cans of pineapple juice.