Howard and Mary shared some erasers equally. After Mary bought 78 erasers and Howard gave 102 erasers away, they had 570 erasers left. How many erasers did each of them have at first?
| |
Howard |
Mary |
Total |
| Before |
1 u |
1 u |
|
| Change |
+ 78 |
- 102 |
|
| After |
1 u + 78 |
1 u - 102 |
570 |
Howard and Mary had the same number of erasers at first.
Total number of erasers in the end
= 1 u + 78 + 1 u - 102
= 1 u + 1 u + 78 - 102
= 2 u - 24
2 u - 24 = 570
2 u = 570 + 24
2 u = 594
1 u = 594 ÷ 2 = 297
Number of erasers that each of them had at first
= 1 u
= 297
Answer(s): 297
