If a : b : c = 7 : 3 : 5, then (a + b + c) : (2a + b – c) is equal to :

If a : b : c = 7 : 3 : 5, then (a + b + c) : (2a + b – c) is equal to :
[A]1 : 2
[B]2 : 3
[C]3 : 4
[D]5 : 4

5 : 4
a : b :  c = 7 : 3 : 5
=> \frac{a}{7} = \frac{b}{3} = \frac{c}{5} = k (let)
=> a = 7k, b = 3k, c = 5k
Now (a + b + c) : (2a + b - c)
= (7k + 3k + 5k) : (2\times 7k + 3k - 5k)
= 15k : 12k = 5 : 4
Hence option [D] is correct answer.

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