Kathy made 780 tarts and cookies. After she gave 0.1 of the tarts and 0.6 of the cookies to her children, she was left with an equal number of tarts and cookies. How many tarts had she left?
| |
Tarts |
Cookies |
Before
|
10x2 =
20 u |
5x9 =
45 u |
Change
|
- 1x2 =
- 2 u |
- 3x9 =
- 27 u |
After
|
9x2 =
18 u |
2x9 =
18 u |
Comparing tarts and
cookies in the end |
1x18 =
18 u |
1x18 =
18 u |
0.1 =
110 0.6 =
610 =
35 The number of tarts and cookies is the same in the end. Make the number of tarts and cookies in the end the same. LCM of 9 and 2 and 1 is 18.
Total number of tarts and cookies at first
= 20 u + 45 u
= 65 u
65 u = 780
1 u = 780 ÷ 65 = 12
Number of tarts that Kathy had left
= 18 u
= 18 x 12
= 216
Answer(s): 216
