Oscar had to paint some containers. On the first day, the number of containers he painted was 40% of the number of containers that he had not painted. One week later, he painted another 51 containers. As a result, the total number of painted containers became 15 more than
45 of the total number of containers. How many more containers were unpainted than painted on the first day?
|
Painted |
Not painted |
Total |
Before
|
2x5 = 10 u |
5x5 = 25 u |
7x5 = 35 u |
Change |
+ 51 |
- 51 |
|
After |
10 u + 51 |
25 u - 51 |
35 u |
Comparing painted and not painted containers in the end |
4x7 + 15 = 28 u + 15 |
1x7 - 15 = 7 u - 15 |
5x7 = 35 u |
40% =
40100 =
25Painted : Not painted = 2 : 5
The total number of containers remains unchanged. Make the total number of containers at first and in the end the same. LCM of 7 and 5 is 35.
The number of containers painted in the end is repeated.
28 u + 15 = 10 u + 51
28 u - 10 u = 51 - 15
18 u = 36
1 u = 36 ÷ 18 = 2
Number of more containers that were not painted than painted on the first day
= 25 u - 10 u
= 15 u
= 15 x 2
= 30
Answer(s): 30