Question

If the probability of a quadrilateral being a square is 0.4 then the probability of the quadrilateral not being a square is ___.

• A. 1
• B. 0.5
• C. 0.6
• D. 0.4

Answer 1

The correct option is C

0.6

let P(S) = probability of quadrilateral being a square.

P(S') = probability of quadrilateral not being a square.

P(S) + P(S') = 1 ($\because$ P(S) and P(S') are complimentary events)

Given P(S) = 0.4

$\Rightarrow$ 0.4 + P(S') = 1

$\Rightarrow$ P(S') = 0.6