Ben had to paint some boxes. On the first day, the number of boxes he painted was 40% of the number of boxes that he had not painted. One week later, he painted another 133 boxes. As a result, the total number of painted boxes became 23 more than ³₅ of the total number of boxes. How many more boxes were unpainted than painted on the first day?

	Painted	Not painted	Total
Before	2x5 = 10 u	5x5 = 25 u	7x5 = 35 u
Change	+ 133	- 133
After	10 u + 133	25 u - 133	35 u
Comparing painted and not painted boxes in the end	3x7 + 23 = 21 u + 23	2x7 - 23 = 14 u - 23	5x7 = 35 u

40% = ⁴⁰₁₀₀ = ²₅
Painted : Not painted = 2 : 5

The total number of boxes remains unchanged. Make the total number of boxes at first and in the end the same.  LCM of 7 and 5 is 35.

The number of boxes painted in the end is repeated.

21 u + 23 = 10 u + 133
21 u - 10 u = 133 - 23
11 u = 110

1 u = 110 ÷ 11 = 10

Number of more boxes that were not painted than painted on the first day
= 25 u - 10 u
= 15 u
= 15 x 10
= 150

Answer(s): 150