A Steel bridge was constructed at a cost of P$85$M in $2005.$ Today is the anniversary of its completion. It is expected to survive another $20$ years, as it stands. What should be the closest estimate of its book value today if sum of years digits depreciation method was applied? Assume that the building has a salvage value of P$30$M when it is to be sold for scrap in $20$ years.

O P $45\mathrm{.}6$ M

~ P$38\mathrm{.}7$M

O P $59\mathrm{.}2$ M

O P $32\mathrm{.}4$ M

C P $52\mathrm{.}5$M SHOW SOLUTION