A bag contains 120 marbles. Some red and the rest are black. There are 19 red marbles for every black marble how many red marbles are In the bag explain your reasoning

In the bag there are 114 red marbles.

Step-by-step explanation:

Analysis

We call x the set of 19 red marbles plus 1 black marble that is a set of 20 marbles.

To calculate the number of sets of 20 marbles that the bag has, we divide 120 by 20. x = 120:20 x = 6 sets

Solution of problem

To obtain the number of red marbles (RM) we multiply the number of sets of marbles by the amount of red marbles that each set has. RM=19*6=114

114

Step-by-step explanation:

Ratio of red marbles to black marbles is 19:1. (Data from 3rd sentence)

19+1 = 20

20 units = 120 (Data from 1st sentence)

1 unit = 120/20 = 6

19 units = 120-6 = 114 (Values solved in working above)

Ans: There are 114 red marbles.