Erika made 520 shortbreads and croissants. After she gave 0.1 of the shortbreads and 0.6 of the croissants to her students, she was left with an equal number of shortbreads and croissants. How many shortbreads had she left?
| |
Shortbreads |
Croissants |
Before
|
10x2 =
20 u |
5x9 =
45 u |
Change
|
- 1x2 =
- 2 u |
- 3x9 =
- 27 u |
After
|
9x2 =
18 u |
2x9 =
18 u |
Comparing shortbreads and
croissants in the end |
1x18 =
18 u |
1x18 =
18 u |
0.1 =
110 0.6 =
610 =
35 The number of shortbreads and croissants is the same in the end. Make the number of shortbreads and croissants in the end the same. LCM of 9 and 2 and 1 is 18.
Total number of shortbreads and croissants at first
= 20 u + 45 u
= 65 u
65 u = 520
1 u = 520 ÷ 65 = 8
Number of shortbreads that Erika had left
= 18 u
= 18 x 8
= 144
Answer(s): 144
