Yer numbers...start=80$ (step=0????)
next month, kost=72, so delta=8, & 8/80=10%...kost go down 10%
month 2...kost=64.8, delta=7.2=10% less than prior month
me spekt take off 10% evree month
so kost=start$*(0.9)^number-months0.9^7=0.4782969000000
end kost=80*0.4782969=
u gotu month 8, that meen 7 months av kost kuts, so last kost=(0.9)^7 *(start-kost)
anser=38.263752
l