Let the mass of the orange be \( x \) grams. According to the problem, the mass of the pineapple would then be \( x + 1920 \) grams.
We know that their total mass is 2080 grams. Therefore, we can set up the following equation:
\[ x + (x + 1920) = 2080 \]
Simplifying this:
\[ 2x + 1920 = 2080 \]
Now, subtract 1920 from both sides:
\[ 2x = 2080 - 1920 \]
\[ 2x = 160 \]
Next, divide both sides by 2:
\[ x = 80 \]
Now that we have the mass of the orange, we can find the mass of the pineapple:
\[ \text{Mass of the pineapple} = x + 1920 = 80 + 1920 = 2000 \text{ grams} \]
Thus, the mass of the pineapple is 2000 grams.