Andy had three boxes, containing a total of 960 styrofoam plates. The number of styrofoam plates in Box W to the total number of styrofoam plates was 3 : 8. He sold 275 styrofoam plates from Box X and sold
15 of the styrofoam plates in Box Y. The number of styrofoam plates left in Box X to the number of styrofoam plates left in Box Y was 5 : 1. How many styrofoam plates were there in Box X at first?
|
Box W |
Box X |
Box Y |
Total |
Before |
3 u
|
5 u (600)
|
8 u (960) |
|
|
20 p + 275 |
5 p |
|
Change |
|
- 275 |
- 1 p |
|
|
|
|
4 p |
|
After |
|
5x4 = 20 p |
1x4 = 4 p |
|
8 u = 960
1 u = 960 ÷ 8 = 120
Number of styrofoam plates in Box X and Box Y at first
= 5 u
= 5 x 120
= 600
The number of plates left in Y is the repeated identity.
LCM of 1 and 4 = 4
20 p + 275 + 5 p = 600
20 p + 5 p = 600 - 275
25 p = 325
1 p = 325 ÷ 25 = 13
Number of plates in Box X at first
= 20 p + 275
= 20 x 13 + 275
= 260 + 275
= 535
Answer(s):535