Ian, Zeph and Daniel had 250 erasers. After Ian used 30 erasers and Zeph used
25 of her erasers, Ian had four times as many erasers left as Zeph. Daniel bought another 40 erasers, he had thrice the number of erasers Zeph had left. How many erasers did Daniel have at first?
| |
Ian |
Zeph |
Daniel |
Total |
| Before |
12 u + 30 |
5 u |
9 u - 40 |
250 |
| Change |
- 30 |
- 2 u |
+ 40 |
|
| After |
12 u |
3 u |
9 u |
|
Comparing Ian
and Zeph in the end |
4 |
1 |
|
|
Comparing Daniel
and Zeph in the end |
|
1 |
3 |
|
Number of erasers that Ian had in the end
= 4 x 3 u
= 12 u
Number of erasers that Daniel had in the end
= 3 x 3 u
= 9 u
Total number of erasers at first
= 12 u + 30 + 5 u + 9 u - 40
= 26 u - 10
26 u - 10 = 250
26 u = 250 + 10
26 u = 260
1 u = 260 ÷ 26 = 10
Number of erasers that Daniel had at first
= 9 u - 40
= 9 x 10 - 40
= 90 - 40
= 50
Answer(s): 50
