A total of 70 black pens and brown pens are in a container. The ratio of black pens to brown pens was 1 : 6. Some pink pens and gold pens were put into the container. For every 5 brown pens that were already in the container, 5 gold ones were added. Then, the final number of black pens and pink pens was ²₅ the final number of brown pens and gold pens. Find the total number of pink and gold pens.

Pink pens	Black pens	Brown pens	Gold pens
	1x5	6x5
		5x6	5x6
2x12		5x12
19 u	5 u	30 u	30 u

The number of brown pens is repeated.  Make the number of brown pens the same.  LCM of 6 and 5 is 30.

The total number of brown pens and gold pens is repeated.  Make the total number of brown and gold pens the same.  LCM of 60 and 5 is 60.

Total number of black pens and brown pens
= 5 u + 30 u
= 35 u

35 u = 70

1 u = 70 ÷ 35 = 2

Total number of pink and gold pens
= 19 u + 30 u
= 49 u
= 49 x 2
= 98

Answer(s): 98