A total of 250 white rulers and blue rulers are in a container. The ratio of white rulers to blue rulers was 1 : 4. Some red rulers and grey rulers were put into the container. For every 5 blue rulers that were already in the container, 3 grey ones were added. Then, the final number of white rulers and red rulers was ¹₄ the final number of blue rulers and grey rulers. Find the total number of red and grey rulers.

Red rulers	White rulers	Blue rulers	Grey rulers
	1x5	4x5
		5x4	3x4
1x8		4x8
3 u	5 u	20 u	12 u

The number of blue rulers is repeated.  Make the number of blue rulers the same.  LCM of 4 and 5 is 20.

The total number of blue rulers and grey rulers is repeated.  Make the total number of blue and grey rulers the same.  LCM of 32 and 4 is 32.

Total number of white rulers and blue rulers
= 5 u + 20 u
= 25 u

25 u = 250

1 u = 250 ÷ 25 = 10

Total number of red and grey rulers
= 3 u + 12 u
= 15 u
= 15 x 10
= 150

Answer(s): 150