If a/9 = b/7 = c/6 then find ( (a + b )/(a + b + c ) ).

Given, \(\frac{a}{9}\) = \(\frac{b}{8}\) = \(\frac{c}{7}\)

Here we can directly conclude that 

a = 9, b = 8, c = 7, hence

⇒ (\(\frac{a + b }{a + b + c }\)) = (\(\frac{9 + 8 }{9 + 8 + 7 }\)) = \(\frac{17}{24}\)