A bag contains green marbles and blue marbles, 18 in total. The number of green

marbles is 2 less than 3 times the number of blue marbles. How many green marbles

are there?

Step-by-step explanation:

Let the number of blue marbles be x

The number of green marbles = 3x - 2

Total marbles = 18

x + 3x - 2 = 18

4x - 2 = 18

4x = 18+2

4x = 20

x = 20/4

x = 5

The number of blue marbles = 5

The number of green marbles = 3*5 - 2 = 15 - 2 = 13