Lilly has a bag of 140 colored marbles. the bag has an equal number of green and blue marbles and an equal number of red and yellow marbles. if lilly arranged all of the green marbles in groups of 8 and all of the blue marbles in groups of 7, how many red marbles are in the bag?

Okay. I think to find the number of green and blue marbles each, we have to find the LCM of 8 and 7. The LCM of 8 and 7 is 56. There are 56 green marbles and 56 blue marbles. That a total of 112 marbles combined. 140 - 112 = 28. There are 28 red and yellow marbles. There are an equal number of both. 28/2= 14. There are 14 red marbles in the bag.