At a stall, the ratio of peaches to mandarin oranges was 7 : 10. After Nora bought four-fifths of the mandarin oranges, there was a total of 90 peaches and mandarin oranges left at the stall. How many fruits were there at first?
| |
Peaches |
Mandarin Oranges |
Total |
Comparing peaches
and mandarin oranges at first |
7x1 =
7 u |
10x1 =
10 u |
17 u |
Before |
|
5x2 =
10 u |
|
Change |
|
- 4x2 =
- 8 u |
|
After |
7 u |
1x2 =
2 u |
90 |
The number of mandarin oranges at first is repeated. Make the number of mandarin oranges at first the same. LCM of 10 and 5 is 10.
Total number of fruits left
= 7 u + 2 u
= 9 u
9 u = 90
1 u = 90 ÷ 9 = 10
Number of fruits at first
= 7 u + 10 u
= 17 u
= 17 x 10
= 170
Answer(s): 170
