A square plot of land was divided into 16 equal parts by drawing lines parallel to its sides. How many rectangles (not squares) were formed in the resulting figure?

The logic follows here is,

A square plot of land was divided into 16 equal parts by drawing lines parallel to its sides.

Assume the given square is 4 × 4 units and it is divided into 16 equal parts by intersecting lines parallel to its sides.

Thus, the smallest square will be 1 × 1 units

So, there will be,

• 16 squares of 1 × 1 units
• 9 squares of 2 × 2 units
• 4 squares of 3 × 3 units
• 1 square of 4 × 4 units

The total number of square = 16 + 9 + 4 + 1

= 30

• There will be 30 squares in the resulting figure.

Now, we have to find the number of rectangles, but it will be difficult to find rectangles one by one. 

Here, we know that there are 5 horizontal and 5 vertical lines, so we need to select 2 horizontal ad 2 vertical lines to form a rectangle. Thus, 2 lines can be selected in ⁵C₂ = 10 ways

Therefore, total rectangles (2 horizontal ad 2 vertical ) = 10 × 10

= 100

Now, rectangles (not squares) formed in the given figure:

= Total rectangles - Total squares

= 100 - 30

= 70

Thus, there will be '70' rectangles.

Hence, the correct answer is "70".