Question

A dice has two faces each with number ‘1’, three faces each with number ‘2’ and one face with number ‘3’. If dice is rolled once, determine
(i) P(2) (ii) P(1 or 3) (iii) P(not 3)

Answer 1

Total number of faces on a dice = 6
Number of faces with number 1 = 2
Number of faces with number 2 = 3
Number of faces with number 3 = 1
$\therefore P\left(1\right)=\frac{2}{6}=\frac{1}{3},P\left(2\right)=\frac{3}{6}=\frac{1}{2},P\left(3\right)=\frac{1}{6}$
(i) P $\left(2\right)=\frac{1}{2}$
(ii) P (1 or 3 ) = P(1) + P(3)
$=\frac{1}{3}+\frac{1}{6}=\frac{2+1}{6}=\frac{3}{6}=\frac{1}{2}\left(iii\right)P\left(\text{not 3}\right)=1-P\left(3\right)=1-\frac{1}{6}=\frac{5}{6}$