1 mole of a gas with γ = 7/5 is mixed with 1 mole of a gas with γ = 5/3, then the value of γ for the resulting mixture is

- 2/5
- 24/16
- 12/7
- 7/5

**Answer**

Use the formula

(n_{1}+n_{2})/(γ-1) = n_{1}/(γ_{1}-1) + n_{2}/(γ_{2}-1)

(1+1)/(γ-1) = 1/(7/5 - 1) + 1/(5/3 - 1)

2/(γ-1) = 5/2 + 3/2 = 4

(γ-1) = 1/2

γ = 3/2 or 24/16

**The correct option is B.**