Thanks a ton for the help spt =D!

Hey everyone, desperately need some help with the problem below:


There were some blue marbles and white marbles in a bag. If 70 blue marbles were to be removed from the bag, the ratio of the number of blue marbles to the number of white marbles would be 3:4. If 112 white marbles were to be removed from the bag instead, the ratio of the number of blue marbles to the number of white marbles would be 8:7. If 48 more blue marbles were to be added into the bag, what percentage of all the marbles would be blue marbles?

Thanks in advance!