For example:

Solution:

If there are x watermelons, then wax gourd X- 12 and pumpkin are 3× (X+X- 12).

Judging from the meaning of the question.

X+X- 12+3×(X+X- 12)= 240

Get:

X=36

Wax gourd: 36- 12 = 24 (pieces)

Pumpkin: 3× (72- 12) = 180 (each)

Extended data:

Kilogram is the unit of mass, and mass is equivalent to how "heavy" a thing is every day. However, quality is actually an attribute with "inertia"; In other words, an object will tend to maintain its current speed without external force. When an object with a mass of one kilogram is subjected to a force of one Newton, it will get an acceleration of one meter per square second (about one tenth of the acceleration of the earth's gravity).

Baidu encyclopedia -kg