If a cone is cut into two parts by a horizontal plane passing through the mid-point of its axis, the ratio of the volumes f upper and lower part is (a)   1:2      (b)  2:1    (c)  1:7    (d)  1:8

Explanation

To find the ratio of the volumes of the upper and lower parts of a cone that is cut by a horizontal plane passing through the midpoint of its axis, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Geometry of the Cone**:
- Let the height of the cone be \( h \).
- When the cone is cut by a horizontal plane at the midpoint of its height, each part will have a height of \( \frac{h}{2} \).

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