Lee, Wesley and Daniel had 240 erasers. After Lee used 20 erasers and Wesley used
15 of her erasers, Lee had thrice as many erasers left as Wesley. Daniel bought another 30 erasers, he had twice the number of erasers Wesley had left. How many erasers did Daniel have at first?
| |
Lee |
Wesley |
Daniel |
Total |
| Before |
12 u + 20 |
5 u |
8 u - 30 |
240 |
| Change |
- 20 |
- 1 u |
+ 30 |
|
| After |
12 u |
4 u |
8 u |
|
Comparing Lee
and Wesley in the end |
3 |
1 |
|
|
Comparing Daniel
and Wesley in the end |
|
1 |
2 |
|
Number of erasers that Lee had in the end
= 3 x 4 u
= 12 u
Number of erasers that Daniel had in the end
= 2 x 4 u
= 8 u
Total number of erasers at first
= 12 u + 20 + 5 u + 8 u - 30
= 25 u - 10
25 u - 10 = 240
25 u = 240 + 10
25 u = 250
1 u = 250 ÷ 25 = 10
Number of erasers that Daniel had at first
= 8 u - 30
= 8 x 10 - 30
= 80 - 30
= 50
Answer(s): 50
