how many elves are wrpping presents

Question

five of santas elves can wrap 5 presents in 5 minutes. santa said, in the last hour and 40 minutes, my elves have wrapped 100 presents. how many elves are in santas workshop wraping presents.

Answer 1

5 presents require 25 elf-minutes (5 x 5)

100 presents require 500 minutes, or 8 hours 20 minutes

8 1/3 ÷ 1 2/3

25/3 ÷ 5/3

25/3 · 3/5

5

 

Or

 

In 1 hour 40 minutes 5 elves wrap (100/5)(5) or 100 presents.