First we have to see the formula of profit, which is
![Selling \ price - cost \ price = profit](https://img.qammunity.org/2019/formulas/mathematics/middle-school/yo0t3acrgk5y8z4bzq9jpq2m6p65hy4541.png)
And it is given that profit should be atleast $150, that is
![image](https://img.qammunity.org/2019/formulas/mathematics/middle-school/q733yzwwiaxg2962un9em8d1h31iyapjt1.png)
Let Ritax dollars per cake, so for 15 cakes, she charge 15x .
And she epent 30 dollars for 15 cakes.
So we will get
![15x-30 \geq 150](https://img.qammunity.org/2019/formulas/mathematics/middle-school/9bk4jpi79jfrcp38jzenapayookj9a6q6c.png)
Adding 30 to both sides
![image](https://img.qammunity.org/2019/formulas/mathematics/middle-school/opmxg7b2vrgzoagcxlbrsqoo0hib0kc3fx.png)
Correct option is the second option .