10 people who build at the same rate can frame a house in 6 days. That means it will take one person [tex] 10\times6=60 [/tex] days to finish the house.
Which means that it will take 4 people [tex] \frac{60}{4}=15 [/tex] days to finish the house.
So, the fractional part of the house 4 people can frame in 3 days will be [tex] \frac{3}{15}=\frac{1}{5} [/tex]
Thus, Option D is the correct answer.
