Tenths is the correct answer because the first digit after the decimal represents the tenths place. the next digit after the decimal represents the hundredths place the remaining digits continue to fill in the place values until there are no digits left.
So 48 • 4 would equal 192 so 4 • 2 mins equals 8 mins and then you have 8 more books to unpack so 48 divide by 8 equals 6. So the answer would bc (8 mins and 6 second)