its is asking x(1+z/100) is > | < y(1+z/400)^4
a gives x(1+4/100) and y(1+4/400) ^ 4
so since we have no idea of x and y nothing can be concluded.
b x(1+z/100) = x + y
and y(1+z/400)^4 = y^4
* (z/400) + 6 y^2
* (z/400)^2 + 4y
* (z/400)^3 + (z/400)^4
gives y(1+z/400)^4 > than x+y. since x,y and z are all >0 but <50.
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