Natalie spent ⁴₅ of her money on 12 notebooks and 8 staplers. The cost of each stapler is 3 times the cost of each notebook. She bought some more notebooks with ²₃ of her remaining money. How many notebooks did Natalie buy altogether?

12 notebooks + 8 staplers		Remaining  amount		Total amount
4 p = 36 u		1 p = 9 u		5 p
12 notebooks	8 staplers	More notebooks	Left
		2	1
12 u	24 u	6 u

Cost of 1 notebook = 1 u
Cost of 1 stapler = 3 u

Cost of 12 notebooks = 12 x 1 u = 12 u
Cost of 8 staplers = 8 x 3 u = 24 u

Cost of 12 notebooks + 8 staplers
= 12 u + 24 u
= 36 u

4 p = 36 u

1 p = 36 u ÷ 4 = 9 u

Amount of remaining money that Natalie spent on buying more notebooks
= ²₃ x 9 u
= 6 u

Number of notebooks that Natalie bought with ²₃ of her remaining money
= 6 u ÷ 1 u
= 6

Total number of notebooks that Natalie bought
= 12 + 6
= 18

Answer(s): 18