David had to paint some containers. On the first day, the number of containers he painted was 30% of the number of containers that he had not painted. One week later, he painted another 380 containers. As a result, the total number of painted containers became 20 more than
35 of the total number of containers. How many less containers were painted than unpainted on the first day?
|
Painted |
Not painted |
Total |
Before
|
3x5 = 15 u |
10x5 = 50 u |
13x5 = 65 u |
Change |
+ 380 |
- 380 |
|
After |
15 u + 380 |
50 u - 380 |
65 u |
Comparing painted and not painted containers in the end |
3x13 + 20 = 39 u + 20 |
2x13 - 20 = 26 u - 20 |
5x13 = 65 u |
30% =
30100 =
310Painted : Not painted = 3 : 10
The total number of containers remains unchanged. Make the total number of containers at first and in the end the same. LCM of 13 and 5 is 65.
The number of containers painted in the end is repeated.
39 u + 20 = 15 u + 380
39 u - 15 u = 380 - 20
24 u = 360
1 u = 360 ÷ 24 = 15
Number of less containers that were painted than not painted on the first day
= 50 u - 15 u
= 35 u
= 35 x 15
= 525
Answer(s): 525