Question

If a:b:c = 6:7:8 and 𝑐 =10, what is the value of 𝑎 +𝑏 +𝑐?

Answer 1

Let the common factor be k. Then a = 6k, b = 7k, c = 8k. Since c = 10, 8k = 10 ⇒ k = 10/8 = 5/4.

So a + b + c = (6 + 7 + 8)k = 21 · (5/4) = 105/4 = 26.25.