Answer:
Option (C)
Step-by-step explanation:
In the given circle, AB is a chord passing through the center O.
Therefore,chord AB is a diameter of the circle and OC is the radius.
AO = OB = OC
OC⊥AB, and length of OC = 7 cm
By applying Pythagoras theorem in right ΔBOC,
BC² = OC² + OB²
BC = 
= 
=
≈ 9.9 units
Therefore, Option (C) will be the answer.
N+7 - 7 more songs added
n-2 - 2 songs deleted (subtracted)
4n - 4 times more songs than before
n/2 - the number of songs cut in half (divided by 2)