A total of 81 pink pencils and white pencils are in a container. The ratio of pink pencils to white pencils was 1 : 2. Some red pencils and gold pencils were put into the container. For every 9 white pencils that were already in the container, 11 gold ones were added. Then, the final number of pink pencils and red pencils was ²₅ the final number of white pencils and gold pencils. Find the total number of red and gold pencils.

Red pencils	Pink pencils	White pencils	Gold pencils
	1x9	2x9
		9x2	11x2
2x8		5x8
7 u	9 u	18 u	22 u

The number of white pencils is repeated.  Make the number of white pencils the same.  LCM of 2 and 9 is 18.

The total number of white pencils and gold pencils is repeated.  Make the total number of white and gold pencils the same.  LCM of 40 and 5 is 40.

Total number of pink pencils and white pencils
= 9 u + 18 u
= 27 u

27 u = 81

1 u = 81 ÷ 27 = 3

Total number of red and gold pencils
= 7 u + 22 u
= 29 u
= 29 x 3
= 87

Answer(s): 87