There were 72 persimmons and mangosteens in a stall at first. After
17 of the persimmons and
12 of the mangosteens were sold, there were a total of 51 persimmons and mangosteens now. How many persimmons were there at first?
| |
Persimmons |
Mangosteens |
Total |
| Before |
7 u |
2 p |
72 |
| Change |
- 1 u |
- 1 p |
- 21 |
| After |
6 u |
1 p |
51 |
Total number of persimmons and mangosteens sold
= 72 - 51
= 21
6 u + 1 p = 51
1 p = 51 - 6 u --- (1)
1 u + 1 p = 21
1 p = 21 - 1 u --- (2)
(2) = (1)
21 - 1 u = 51 - 6 u
6 u - 1 u = 51 - 21
5 u = 30
1 u = 30 ÷ 5 = 6
Number of persimmons at first
= 7 u
= 7 x 6
= 42
Answer(s): 42
