The current erection cost of a structure is Rs. $13,200$. If the labour wages per day increase by $\frac 1 5$ of the current wages and the working hours decrease by $\frac 1 {24}$ of the current period, then the new cost of erection in Rs. is
$(A)\ 16,500$.
$(B)\ 15,180$.
$(C)\ 11,000$.
$(D)\ 10,120$.
I have got an answer different from the answer which is approximately equal to $16528$. Which is very close to option $(A)$. Is it correct? Please help me in this regard.
Thank you very much.
Attempt:
Labour wages increment is proportional to erection cost and working hours decrement is reverse proportional to the erection cost.
So the required erection cost is $13200×\frac{\frac65}{\frac{23}{24}}$ which simplifies to $16528$ (approx.)