Final answer:
Each sibling has 639 grams of grapes.
Step-by-step explanation:
To find out how many grams of grapes each sibling has, we need to subtract the grams of grapes Sasha gave to Kari and the grams of grapes Kari shared with the twins from the total number of grams of grapes Sasha had.
So, Sasha had 1 kilogram, which is equal to 1000 grams, of grapes. She gave 763 grams to Kari. Kari then shared 598 grams with the twins.
To find out how many grams of grapes each sibling has, we can subtract the total grams shared from the total grams Sasha had: 1000 - 763 - 598 = 639 grams. Therefore, each sibling has 639 grams of grapes.