There were 279 mangoes and lemons in a fruit stall.
310 of the mangoes and
37 of lemons were sold. Given that there were 171 mangoes and lemons left, how many mangoes were there in the fruit stall at first?
|
Mangoes |
Lemons |
Before |
10 u |
7 p |
Change |
- 3 u |
- 3 p |
After |
7 u |
4 p |
10 u + 7 p = 279 --- (1)
7 u + 4 p = 171 --- (2)
Make p the same.
(1)
x 4 40 u + 28 p = 1116 --- (3)
(2)
x 7 49 u + 28 p = 1197 --- (4)
(4) - (3)
49 u - 40 u = 1197 - 1116
9 u = 81
1 u = 81 ÷ 9 = 9
Number of mangoes at first
= 10 u
= 10 x 9
= 90
Answer(s): 90