Shiyun had some lemon and persimmon face masks.
14 of them were lemon. She gave away
15 of the lemon face masks and
15 of the persimmon face masks. In the end, she had 128 lemon and persimmon face masks altogether. How many persimmon face masks did Shiyun have at first?
| |
Lemon face masks |
Persimmon face masks |
Total |
Comparing lemon and persimmon face masks
at first |
1x5 =
5 u |
3x5 =
15 u |
4x5 =
20 u |
Before |
5 u |
5x3 =
15 u |
|
Change |
- 1 u |
- 1x3 =
- 3 u |
|
After |
4 u |
4x3 =
12 u |
|
The number of persimmon face masks at first is repeated. Make the number of persimmon face masks the same. LCM of 3 and 5 is 15.
Total number of face masks in the end
= 4 u + 12 u
= 16 u
16 u = 128
1 u = 128 ÷ 16 = 8
Number of persimmon masks at first
= 15 u
= 15 x 8
= 120
Answer(s): 120
