The club needs to make and sell 29 t-shirts in order to profit at least 150.
Explanation
Suppose , the number of t-shirts the club needs to make and sell is [tex]x[/tex]
Selling price of each t-shirt is 15, so the total selling price of [tex]x[/tex] t-shirts [tex]= 15x[/tex]
It costs 20 plus 9 per t-shirt to make the t-shirts. So, the total making cost of [tex]x[/tex] t-shirts [tex]= 20+9x[/tex]
Now for getting profit at least 150 , the equation will be.....
[tex]15x-(20+9x)= 150\\ \\ 15x-20-9x=150\\ \\ 6x-20=150\\ \\ 6x=150+20=170\\ \\ x= \frac{170}{6}=28.333....[/tex]
It means the value of x should be at least 28.333...
As here x is the number of t-shirts and it can't be in decimal , so the minimum value of x will be 29.
