[Question]: At a school, 40% of the students receive a free lunch. These lunches are paid for by making sure the price paid by the paying students is enough to cover everyone's meal. If it costs $210 to feed 50 students, how much do the paying students pay for lunch?
[Answer]: 60% of the students pay for the lunch because 100 - 40 = 60. 30 students pay for lunch because 50 x .6 = 30. These students pay $7 for their lunch because 210 / 30 = 7.
So the answer is 7.

[Question]: Three friends Wolfgang, Ludo, and Michael, went to Walmart and bought marbles. Wolfgang bought 16 marbles, Ludo bought 1/4 times more marbles than Wolfgang, and Michael bought 2/3 times as many marbles as the number of marbles both Wolfgang and Ludo bought. If they combined their marbles and decided to share them equally, how many marbles did each get?
[Answer]: Ludo bought 1 / 4 more marbles than Wolfgang, which is 1 / 4 * 16 marbles = 4 marbles. The total number of marbles that Ludo bought is 16 marbles + 4 marbles = 20 marbles. Wolfgang and Ludo purchased a total of 20 marbles + 16 marbles = 36 marbles. If Michael bought 2 / 3 times the total number of marbles bought by Wolfgang and Ludo, he bought 2 / 3 * 36 marbles = 24 marbles. The three friends purchased a total of 24 marbles + 36 marbles = 60 marbles. When they shared the marbles equally, each got 60 marbles / 3 people = 20 marbles / person.
So the answer is 20.

[Question]: A busy port has 4 cruise ships and twice as many cargo ships. The number of sailboats is 6 more than the cargo ships and seven times more than fishing boats. How many vessels are there on the water?
[Answer]:
There are 4 x 2 = 8 cargo ships. There are 8 + 6 = 14 sailboats. There are 14 / 7 = 2 fishing boats. There are 4 + 8 + 14 + 2 = 28 vessels on the water.
So the answer is 28.