A total of 88 grey pens and brown pens are in a container. The ratio of grey pens to brown pens was 1 : 3. Some red pens and green pens were put into the container. For every 6 brown pens that were already in the container, 9 green ones were added. Then, the final number of grey pens and red pens was ²₃ the final number of brown pens and green pens. Find the total number of red and green pens.

Red pens	Grey pens	Brown pens	Green pens
	1x2	3x2
		6x1	9x1
2x5		3x5
8 u	2 u	6 u	9 u

The number of brown pens is repeated.  Make the number of brown pens the same.  LCM of 3 and 6 is 6.

The total number of brown pens and green pens is repeated.  Make the total number of brown and green pens the same.  LCM of 15 and 3 is 15.

Total number of grey pens and brown pens
= 2 u + 6 u
= 8 u

8 u = 88

1 u = 88 ÷ 8 = 11

Total number of red and green pens
= 8 u + 9 u
= 17 u
= 17 x 11
= 187

Answer(s): 187