Dana made 220 biscuits and shortbreads. After she gave 0.1 of the biscuits and 0.8 of the shortbreads to her friends, she was left with an equal number of biscuits and shortbreads. How many biscuits had she left?
| |
Biscuits |
Shortbreads |
Before
|
10x1 =
10 u |
5x9 =
45 u |
Change
|
- 1x1 =
- 1 u |
- 4x9 =
- 36 u |
After
|
9x1 =
9 u |
1x9 =
9 u |
Comparing biscuits and
shortbreads in the end |
1x9 =
9 u |
1x9 =
9 u |
0.1 =
110 0.8 =
810 =
45 The number of biscuits and shortbreads is the same in the end. Make the number of biscuits and shortbreads in the end the same. LCM of 9 and 1 and 1 is 9.
Total number of biscuits and shortbreads at first
= 10 u + 45 u
= 55 u
55 u = 220
1 u = 220 ÷ 55 = 4
Number of biscuits that Dana had left
= 9 u
= 9 x 4
= 36
Answer(s): 36
