Min had some apple and starfruit face masks.
16 of them were apple. She gave away
13 of the apple face masks and
13 of the starfruit face masks. In the end, she had 180 apple and starfruit face masks altogether. How many starfruit face masks did Min have at first?
| |
Apple face masks |
Starfruit face masks |
Total |
Comparing apple and starfruit face masks
at first |
1x3 =
3 u |
5x3 =
15 u |
6x3 =
18 u |
Before |
3 u |
3x5 =
15 u |
|
Change |
- 1 u |
- 1x5 =
- 5 u |
|
After |
2 u |
2x5 =
10 u |
|
The number of starfruit face masks at first is repeated. Make the number of starfruit face masks the same. LCM of 5 and 3 is 15.
Total number of face masks in the end
= 2 u + 10 u
= 12 u
12 u = 180
1 u = 180 ÷ 12 = 15
Number of starfruit masks at first
= 15 u
= 15 x 15
= 225
Answer(s): 225
