Ans 1:
Class : Class 6
the question has been incorrectly framed. The text Jay was "3x times older" is misleading . older implies addition , so it becomes confusing why both multiplication and addition have been mentioned. Instead it should have been - 5 years ago, Jay's age was 3x times that of Trishika's age at that time.
of total marbles to her sister and 50 marbles to her brother. What fraction of the marbles is left with her?