Given : A spherical ball was cut into eight equal pieces along the same axis (as shown in figure).
DI Question : The total surface area of the eight pieces is how much more, in square units, than the original surface area of the spherical ball? [ The surface area of the sphere = 4ΠR2]
So, total surface area of one piece = 1/8*(4ΠR^2) + 1/2 ΠR^2 + 1/2 ΠR^2 = 3/2 ΠR^2
Total surface area of 8 pieces = 8 * 3/2 ΠR^2 = 12 ΠR^2
So, total surface area of the eight pieces is more, in square units, than the original surface area of the spherical ball by 12 ΠR^2 - 4 ΠR^2 = 8 ΠR^2.
Statement (1) : The diameter of the spherical ball = 10 units.
Since Diameter is given, hence radius is known. So we can calculate the value.
SUFFICIENT Statement (2) : The total surface area of eight halves is 3 times that of the original surface area.
This doesn't add any extra information and hence we can't calculate the value.
SUFFICIENT
Answer A
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