Answer:
B. 39.918 cm
Step-by-step explanation:
We know that the length of the first swing, the arc is 65 cm, and the successive swing the arc is 85% of the length of the previous swing.
The problem is asking for the length of the arc on the fourth swing:
We know that the arc of every consecutive swing will be 85% of the swing before, and we know that 85% = 0.85
So the length of the arc of the second swing will be:
85% * length of the arc on the first swing, or
<em>0.85 * 65 cm = 55.25 cm</em>
Now, to know the length of the arc on the third swing we multiply the length of the arc on the second swing times 0.85:
<em>0.85 * 55.25 cm = 46.962 cm</em>
And finally, the length of the arc on the fourth swing will be the length of the arc in the third swing times 0.85:
0.85 * 46.962 cm = 39.918 cm
