Answer:
They collect together
![406\ seashells](https://img.qammunity.org/2020/formulas/mathematics/high-school/3gjtg5hnmfd9x6jjgtu0ayqxuu052u7yql.png)
Explanation:
Let
x-----> number of seashells collected by Amin
y-----> number of seashells collected by Barb
z-----> number of seashells collected by Curt
we know that
![(x)/(y)=(10)/(12)](https://img.qammunity.org/2020/formulas/mathematics/high-school/synxdul2ldr8w1ffrqbgrqef4w7hnj9ovj.png)
------> equation A
![(x)/(z)=(10)/(7)](https://img.qammunity.org/2020/formulas/mathematics/high-school/owa48284lq51iebsp2trmecu27myhiaykm.png)
------> equation B
![(y)/(z)=(12)/(7)](https://img.qammunity.org/2020/formulas/mathematics/high-school/pt5xo8esb03n4jtkgljn5rao3xdbu6yh6w.png)
------> equation C
In this problem we have
![z=98\ seashells](https://img.qammunity.org/2020/formulas/mathematics/high-school/sis0q7vq6k0b04z4tyjcg9dtbkj7g4n9gn.png)
Find the value of x ------> equation B
substitute the value of z
![x=(10)/(7)(98)=140\ seashells](https://img.qammunity.org/2020/formulas/mathematics/high-school/b7zulkebkctyw2ufncb8emgcupccb4s1z7.png)
Find the value of y ------> equation C
substitute the value of z
![y=(12)/(7)(98)=168\ seashells](https://img.qammunity.org/2020/formulas/mathematics/high-school/l0bxesdv2s8kbnyuu3oht1w0jbpbhci8id.png)
therefore
They collect together
![x+y+z=140+168+98=406\ seashells](https://img.qammunity.org/2020/formulas/mathematics/high-school/tcmy7xup7oyj6qdwdnphzi3z8fsc2jzv8e.png)