Answer:
Cost of first book is $18
Cost of second book is $27
Step-by-step explanation:
Given : The bookstore bought two books for $45, with a profit of 40%. If the first book's profit was 25% and the second one's profit was 50%.
To find : The cost of each book.
Solution :
Let x be the cost of first book.
Let y be the cost of second book.
The bookstore bought two books for $45
i.e, [tex]x+y=45[/tex] .......[1]
The first book's profit was 25%
i.e, 25% of x is [tex]\frac{25}{100}\times x=0.25x[/tex]
The second one's profit was 50%.
i.e, 50% of y is [tex]\frac{50}{100}\times x=0.50y[/tex]
Book bought at $45 with profit 40%
[tex]\frac{40}{100}\times 45=18[/tex]
i.e, [tex]0.25x+0.50y=18[/tex] .......[2]
Solving equation [1] and [2]
Substitute x=45-y from [1] in [2]
[tex]0.25x+0.50y=18[/tex]
[tex]0.25(45-y)+0.50y=18[/tex]
[tex]11.25-0.25y+0.50y=18[/tex]
[tex]0.25y=6.75[/tex]
[tex]y=27[/tex]
Put back in [1]
[tex]x+27=45[/tex]
[tex]x=18[/tex]
Therefore, Cost of first book is $18
Cost of second book is $27
