It is given that the circumference of the circle is 19.5 inches. Let the diameter is d inches .
And the formula of circumference is

Substituting the value of C, we will get

When the diameter increased by 3, then the circumference is

And the circumference , when diameter is increased by 3 is 29 inches .
I would just round up to 200 and then subtract twelve or just subtract 200 what ever way u prefer.
Answer:
I came up with -12
Step-by-step explanation:
8 workers = 6 days to complete
x workers = 4 days faster to complete
6/4=1.5 days faster
1.5 x 8 = 12 workers needed to complete the wall in fours days
Usually you are given more information about the rectangle such as distance of length in terms of width.
You know that the formula for perimeter is
P=2(l+w)
Substitute p and the other values to find width.
Hope I helped :)