# The IUPAC name of $CH_3COCH(CH_3)_2$ is

$(a)\;2-methyl-3-butanone \\(b)\;4-methylisopropyl \;ketone \\(c)\;3-methyl-2-butanone \\(d)\;Isopropyl \;mrthyl\;ketone$

lowest sum of locants $=2+3=5$
$3-methyl-2-butanone$ is correct answer.
Hence c is the correct answer.