JAMB - Mathematics (1995 - No. 40)
A die has four of it's faces coloured white and the remaining two coloured black. What is the probability that when the die is thrown two consecutive time, the top face will be white in both cases?
\(\frac{5}{3}\)
\(\frac{1}{9}\)
\(\frac{4}{9}\)
\(\frac{1}{36}\)
Explication
\(\begin{array}{c|c} & W & W & W & W & B & B \\ \hline W & WW & WW & WW & WW & WB & WB \\ W & WW & WW & WW & WW & WB & WB\\W & WW & WW & WW & WW & WB & WB\\ W & WW & WW & WW & WW & WB & WB\\ B & BW & BW & BW & BW & BB & BB \\ B & BW & BW & BW & BW & BB & BB\end{array}\)
P(WW) = \(\frac{16}{36}\)
= \(\frac{4}{9}\)
P(WW) = \(\frac{16}{36}\)
= \(\frac{4}{9}\)