A star is being observed with an 8 bit CCD has a central pixel value of 82 counts when the exposure time is 10 seconds. What would the central pixel value be if the exposure time were 25 seconds? Explain your reasoning

Many of the houses have fireplaces that are 15% efficient and use 15 kg of wood to heat a room to 20 degrees celsius. wanting to reduce their ecological footprint, several of the homeowners are considering switching to woodstoves that are 75 percent efficient. if they do change to using a woodstove, how many kilograms of wood will they save per use?