Answer: 114 marbles
Step-by-step explanation:
From the question, we are told that a bag contains red and black marbles which are 120 marbles in total. We are further told that there are 19 red marbles for every black marble.
Let the number of black marbles be represented by a.
The red marbles will be: = 19 × a = 19a
Based on the information given in the question,
Black marbles + Red marbles = 120
a + 19a = 120
20a = 120
a = 120/20
a = 6
Black marbles = 6
Red marbles = 19a = 19 × 6 = 114 marbles
