question_answer

If\[x,\,y\]and\[z\]are three sums of money such  that \[y\]  is the simple interest on \[x\] and \[z\]is the simple interest on y for the same time and at the same rate, then which one of the following is correct?

A)  \[{{y}^{2}}=xz\]                             

B)  \[2y=x+z\]

C)  \[y=x-z\]                            

D)  \[y=x+z\]