Ethan had to paint some containers. On the first day, the number of containers he painted was 10% of the number of containers that he had not painted. One week later, he painted another 149 containers. As a result, the total number of painted containers became 30 more than ²₅ of the total number of containers. How many less containers were painted than unpainted on the first day?

	Painted	Not painted	Total
Before	1x5 = 5 u	10x5 = 50 u	11x5 = 55 u
Change	+ 149	- 149
After	5 u + 149	50 u - 149	55 u
Comparing painted and not painted containers in the end	2x11 + 30 = 22 u + 30	3x11 - 30 = 33 u - 30	5x11 = 55 u

10% = ¹⁰₁₀₀ = ¹₁₀
Painted : Not painted = 1 : 10

The total number of containers remains unchanged. Make the total number of containers at first and in the end the same.  LCM of 11 and 5 is 55.

The number of containers painted in the end is repeated.

22 u + 30 = 5 u + 149
22 u - 5 u = 149 - 30
17 u = 119

1 u = 119 ÷ 17 = 7

Number of less containers that were painted than not painted on the first day
= 50 u - 5 u
= 45 u
= 45 x 7
= 315

Answer(s): 315