8th Class Mental Ability Mensuration Question Bank Mensuration

An ant is moving around a few food pieces of different shapes scattered on the floor. For which food-piece would the ant have to take a longer round?

A) Food Piece

B)        Food Piece (b)

C) Food Piece

D)       Food Pieces and (b)

E) None of these

Correct Answer: B

Solution :

Explanation Option [b] is correct.

[a] Perimeter = \[\frac{\pi \times d}{2}+d=\frac{22}{7}\times \frac{2.8}{2}+2.8=4.4+2.8=7.2\,cm\]

[b] Perimeter = \[\frac{\pi \times d}{2}+2\] breadth + length \[=4.4+3+2.8=10.2\text{ }cm\] (perimeter of semicircular part is same as in [a]

[c] Perimeter = \[\frac{\pi \times d}{2}+2\] slant height \[=4.4+4=8.4\text{ }cm\]

So, the food shape in [b] requires the ant to cover the longest distance.