A total of 42 grey markers and yellow markers are in a container. The ratio of grey markers to yellow markers was 1 : 6. Some pink markers and black markers were put into the container. For every 3 yellow markers that were already in the container, 9 black ones were added. Then, the final number of grey markers and pink markers was ¹₃ the final number of yellow markers and black markers. Find the total number of pink and black markers.

Pink markers	Grey markers	Yellow markers	Black markers
	1x1	6x1
		3x2	9x2
1x8		3x8
7 u	1 u	6 u	18 u

The number of yellow markers is repeated.  Make the number of yellow markers the same.  LCM of 6 and 3 is 6.

The total number of yellow markers and black markers is repeated.  Make the total number of yellow and black markers the same.  LCM of 24 and 3 is 24.

Total number of grey markers and yellow markers
= 1 u + 6 u
= 7 u

7 u = 42

1 u = 42 ÷ 7 = 6

Total number of pink and black markers
= 7 u + 18 u
= 25 u
= 25 x 6
= 150

Answer(s): 150