A duck named Donald Duck says “All ducks always lie.”

Based only on the information above, which one of the following statements can be logically inferred with certainty?

A line of symmetry is defined as a line that divides a figure into two parts in a way such that each part is a mirror image of the other part about that line.

The figure below consists of 20 unit squares arranged as shown. In addition to the given black squares, upto 5 more may be coloured black. Which one among the following options depicts the minimum number of boxes that must be coloured black to achieve two lines of symmetry? (The figure is representative)

For the picture shown above, which one of the following is the correct picture representing reflection with respect to the mirror shown as the dotted line?

A survey of 450 students about their subjects of interest resulted in the following outcome.

$$\bullet$$ 150 students are interested in Mathematics.

$$\bullet$$ 200 students are interested in Physics.

$$\bullet$$ 175 students are interested in Chemistry.

$$\bullet$$ 50 students are interested in Mathematics and Physics.

$$\bullet$$ 60 students are interested in Physics and Chemistry.

$$\bullet$$ 40 students are interested in Mathematics and Chemistry.

$$\bullet$$ 30 students are interested in Mathematics, Physics and Chemistry.

$$\bullet$$ Remaining students are interested in Humanities.

Based on the above information, the number of students interested in Humanities is