Answer:
![c=\$37.5](https://img.qammunity.org/2020/formulas/mathematics/middle-school/l9ohq56jyt7llhs1uj5hkyi9xe5yfw9kbq.png)
Explanation:
we know that
A relationship between two variables, x, and y, represent an inverse variation if it can be expressed in the form
or
![y=k/x](https://img.qammunity.org/2020/formulas/mathematics/high-school/o50e4iz2cbwjhxop7sc5xcxdwiguxpycgd.png)
In this problem we have
![c*p=k](https://img.qammunity.org/2020/formulas/mathematics/middle-school/u0jk3g4itp0b5gy21uetu3vsxm1vgcjwna.png)
step 1
Find the value of the constant k
For
![c=30, p=50](https://img.qammunity.org/2020/formulas/mathematics/middle-school/6wqb5tmvlq4o0nid963pikqfpny55gxh0e.png)
substitute
![k=30*50=1,500](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xb5f4kzvh8nfore1wir3a374ft8dktisj4.png)
the equation is
![c*p=1,500](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2jctbein2y7xavcxp2b8u83ljgkojo8dmz.png)
step 2
Find the value of c for
![p=40](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2jv9r0ftu7aw0k5szgfcb0yj1qzdf27zkg.png)
substitute in the equation and solve for c
![c*(40)=1,500](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gl5v3mi7o3a4i2707410kh28bzk8tcpa0y.png)
![c=\$37.5](https://img.qammunity.org/2020/formulas/mathematics/middle-school/l9ohq56jyt7llhs1uj5hkyi9xe5yfw9kbq.png)