turkey-yks 2021 Q40

turkey-yks · Other · yks-ayt Not Maths
A pencil with one end sharpened has the unsharpened part shaped like a right circular cylinder and the sharpened end shaped like a right circular cone with height 1 unit, as shown in the figure.
When the other end of the pencil is sharpened to be identical to the sharpened end and the total length of the pencil remains unchanged, the total volume of the pencil decreases by 5\%.
Accordingly, what is the total length of the pencil in units?
A) 12
B) 14
C) 16
D) 18
E) 20
A pencil with one end sharpened has the unsharpened part shaped like a right circular cylinder and the sharpened end shaped like a right circular cone with height 1 unit, as shown in the figure.

When the other end of the pencil is sharpened to be identical to the sharpened end and the total length of the pencil remains unchanged, the total volume of the pencil decreases by 5\%.

Accordingly, what is the total length of the pencil in units?\\
A) 12\\
B) 14\\
C) 16\\
D) 18\\
E) 20