Um... it'll take each pipe 80 mins, bcz if together they take that long, then to find the pipes time separately, you just multiply it by two to show it doing the work the other pipe did as well. Is that what you wanted??
The circumference of a circle is calculated through the equation,
C = 2πr
where C is circumference and r is radius. For this item, I assume that 12 in is the radius such that,
C = 2π(12 in) = 24π
Thus, the circumference of the circle is 24π inches.
The one in the top left corner is the answer
Let's call the width: w
the lenght is then 3w+4 ("4 more than 3 times the width")
and the parameter would be 2(w+3w+4), that is 2*(4w+4), that is 8w+8.
this is also equal to 18.4:
8w+8=18.4
8w=10.4
w=1.3
this is the width, and the lenght is:
4+3*1,3=4+3.9=7.9
and the area is their product:
1.3*7.9=10.27
