Betty made 105 shortbreads and cookies. After she gave 0.7 of the shortbreads and 0.6 of the cookies to her boys, she was left with an equal number of shortbreads and cookies. How many shortbreads had she left?
| |
Shortbreads |
Cookies |
Before
|
10x2 =
20 u |
5x3 =
15 u |
Change
|
- 7x2 =
- 14 u |
- 3x3 =
- 9 u |
After
|
3x2 =
6 u |
2x3 =
6 u |
Comparing shortbreads and
cookies in the end |
1x6 =
6 u |
1x6 =
6 u |
0.7 =
710 0.6 =
610 =
35 The number of shortbreads and cookies is the same in the end. Make the number of shortbreads and cookies in the end the same. LCM of 3 and 2 and 1 is 6.
Total number of shortbreads and cookies at first
= 20 u + 15 u
= 35 u
35 u = 105
1 u = 105 ÷ 35 = 3
Number of shortbreads that Betty had left
= 6 u
= 6 x 3
= 18
Answer(s): 18
