question_answer

If\[{{\log }_{10}}m+{{\log }_{10}}n={{\log }_{10}}(m+n)\]and\[m=7\], then the value of n is

A)  5                            

B)         \[\frac{2}{3}\]

C)  \[\frac{7}{6}\]                   

D)         \[\frac{3}{4}\]