Cindy made 325 cookies and biscuits. After she gave 0.1 of the cookies and 0.6 of the biscuits to her students, she was left with an equal number of cookies and biscuits. How many cookies had she left?
| |
Cookies |
Biscuits |
Before
|
10x2 =
20 u |
5x9 =
45 u |
Change
|
- 1x2 =
- 2 u |
- 3x9 =
- 27 u |
After
|
9x2 =
18 u |
2x9 =
18 u |
Comparing cookies and
biscuits in the end |
1x18 =
18 u |
1x18 =
18 u |
0.1 =
110 0.6 =
610 =
35 The number of cookies and biscuits is the same in the end. Make the number of cookies and biscuits in the end the same. LCM of 9 and 2 and 1 is 18.
Total number of cookies and biscuits at first
= 20 u + 45 u
= 65 u
65 u = 325
1 u = 325 ÷ 65 = 5
Number of cookies that Cindy had left
= 18 u
= 18 x 5
= 90
Answer(s): 90
