Answer:
The answer to your question is: letter c (96%)
Explanation:
Indium -113 (112-9040580 amu) ₁₁₃In
Indium-115 (114.9038780 amu) ₁₁₅In
Atomic mass of Indium is 114.82 amu ₁₁₄.₈₂In
Formula
Atomic mass = m₁(%₁) +m₂(%₂) / 100
%₁ = x I established this is an equation
%₂ = 100 - x
Substituting values
114.82 = 112.8040x + 114.9039(100-x) /100 and know we expand and simplify
114.82 = 112.8040x + 11490.39 - 114.9039x /100
11482 = 112.8040x -114.9039x +11490.39
11482 - 11490.39 = 112.8040x -114.9039x
-8.39 = -2.099x
x = 3.99
Then % of Indium-115 = 100 - 3.99 = 96
