60/8 = 7.4. The dog is faster. 35/5 = 7
First, I'd like to say that this question is flawed because the diameter of the spool changes as you pull the line out. Some would argue it's negligible I suppose.
At any rate, assuming there's a magic spool where the diameter doesn't change, let's find the cicumference so we can find the length of one wrap around the spool.
circumference = 2*pi*r = 2 * pi * 4cm = about 25.133 cm
Now if it turns 16 times we'll have 16 times the circumference.
16 * (25.133 cm)
= 402.128 cm
10 people who build at the same rate can frame a house in 6 days. That means it will take one person
days to finish the house.
Which means that it will take 4 people
days to finish the house.
So, the fractional part of the house 4 people can frame in 3 days will be 
Thus, Option D is the correct answer.
Well the answer is A) about 25