Henry, Simon and Daniel had 144 erasers. After Henry used 8 erasers and Simon used
17 of her erasers, Henry had thrice as many erasers left as Simon. Daniel bought another 12 erasers, he had twice the number of erasers Simon had left. How many erasers did Daniel have at first?
| |
Henry |
Simon |
Daniel |
Total |
| Before |
18 u + 8 |
7 u |
12 u - 12 |
144 |
| Change |
- 8 |
- 1 u |
+ 12 |
|
| After |
18 u |
6 u |
12 u |
|
Comparing Henry
and Simon in the end |
3 |
1 |
|
|
Comparing Daniel
and Simon in the end |
|
1 |
2 |
|
Number of erasers that Henry had in the end
= 3 x 6 u
= 18 u
Number of erasers that Daniel had in the end
= 2 x 6 u
= 12 u
Total number of erasers at first
= 18 u + 8 + 7 u + 12 u - 12
= 37 u - 4
37 u - 4 = 144
37 u = 144 + 4
37 u = 148
1 u = 148 ÷ 37 = 4
Number of erasers that Daniel had at first
= 12 u - 12
= 12 x 4 - 12
= 48 - 12
= 36
Answer(s): 36
