Add up the three situations of "apples and strawberries * * * weigh 980g, pineapples and strawberries * * * weigh 870g, and apples and pineapples * * * weigh 350g", and the sum of the three fruits is 2,200kg.

So the sum of the weights of three fruits is 1 100 kg.

Substituting this conclusion into the above situation,

The weight of pineapple is1100-980 =120kg.

The weight of apples is 1 100-870=230 Jin.

The weight of strawberries is 1 100-350=750 Jin.