Conclusions:

At least some hills being lake is a possibility.

Some mountains are hills.

Statements:

Statements – 1:All Hills are Mountains. All hills are rivers. No hill is a lake.

Statements – 2: All Hills are Mountains. All Mountains are rivers. No river is a lake.

Statements – 3: Some Hills are Mountains. Some hills are rivers. No hill is a lake.

Statements – 4: Some Hills are Mountains. All Mountains are rivers. No hill is a lake.

Statements – 5: All Hills are Mountains. Some hills are rivers. No river is a lake.