Erika spent
45 of her money on 12 notebooks and 9 markers. The cost of each marker is 4 times the cost of each notebook. She bought some more notebooks with
12 of her remaining money. How many notebooks did Erika buy altogether?
| 12 notebooks + 9 markers |
Remaining
amount |
Total
amount |
| 4 p = 48 u |
1 p = 12 u |
5 p |
12
notebooks |
9
markers |
More notebooks |
Left |
|
| |
|
1 |
1 |
|
| 12 u |
36 u |
6 u |
|
|
Cost of 1 notebook = 1 u
Cost of 1 marker = 4 u
Cost of 12 notebooks = 12 x 1 u = 12 u
Cost of 9 markers = 9 x 4 u = 36 u
Cost of 12 notebooks + 9 markers
= 12 u + 36 u
= 48 u
4 p = 48 u
1 p = 48 u ÷ 4 = 12 u
Amount of remaining money that Erika spent on buying more notebooks
=
12 x 12 u
= 6 u
Number of notebooks that Erika bought with
12 of her remaining money
= 6 u ÷ 1 u
= 6
Total number of notebooks that Erika bought
= 12 + 6
= 18
Answer(s): 18
