There are 126 blue marbles.
Total marbles in the bag=150
There are 21 blue marbles for every 4 white marbles then the sequence will be⇒ 4+21+4+21+4+21+4+21+4+21+4+21=150
21 blue marbles appear 6 times for every 4 blue marbles
So 21×6=126 blue marbles and 4×6=24, then 126+24=150 total marbles
∴There will be a total of 126 blue marbles along with 24 white marbles among the 150 marbles.