<h3>Problem Solution</h3>
Assuming the spool is a cylinder and the circumference we're winding around is that of a circle with the given area, we can write the relation between circumference and area as
... C = 2√(πA)
10 times the circumference is then
... 10C = 20√(π·20 cm²) = 40√(5π) cm ≈ 159 cm
<h3>Formula Derivation</h3>
The usual formulas for circumference and area are
... C = 2πr
... A = πr²
If we multiply the area formula by π and take the square root, we get
... πA = (πr)²
... √(πA) = πr
Multiplying this by 2 gives circumference.
... C = 2√(πA) = 2πr
3 times 4 is equal to 12
8 times 4 is equal to 32
therefore 3:8 is equal to 12:32
hope this helps
The probability 2/3 means that there are 2 events we are interested in (which probability to happen we calculate) and there are 3 total events that may happen.
The probability 2/3 is equal to the probability 2/3*2/2=4/6.
An possible outcome would be : The probability that the side of the backgammon can be divided with 8 (there are 4 possibilities: 8, 16, 2 and 64).
3+8*A=3*2*A-1 (I do not really know what the number is so i put A there
