Answer: The answer is 114.
Step-by-step explanation: Let 'n' be the number of black marbles in the bag.
Then, according to the question, there will be '19n' number of red marbles in the bag.
Since there are total 120 marbles in the bag, so we have
[tex] n+19n=120\\\\\Rightarrow 20n=120\\\\\Rightarrow n=6.[/tex]
Therefore, Number of red marbles in the bag will be
[tex] 19n=19\times 6=114.[/tex]
Thus, there are 114 red marbles.
