C-04-Q158mediumsingle_mcqlog20400=?\log_{20} 400 = ?log20400=? (Ex 4.2 Q1)a111b222c202020d400400400ব্যাখ্যা400=202400 = 20^2400=202, so log20400=2\log_{20} 400 = 2log20400=2.