Answer:
Krystal collected 315 pop-can tabs while Natasha collected 565 pop-can tabs.
Explanation:
Let x be number of pop-can tabs Krystal collected
Krystal: x
Natasha: x + 250
x + x + 250 = 880
2x = 880 - 250
2x = 630
x = 315
Krystal: 315 pop-can tabs
Natasha: 315+250 = 565 pop-can tabs