Cost of capital without inflation

Hello Sir,

In chapter 8 example 6 ,
in part b you have used the The Fisher formula (1 + i) = (1 + r) (1 + h)

to remove the effect of inflation from the cost of capital rate

you said that the cost of capital is 15% but here how do we know that this rate is with inflation since the inflation rate is given separately so how can we assume that the rate of 15% is with inflation.

Thanks.