Test Index

WAEC Mathematics 2010 Paper

© africaexams.com

Question : 34

Total: 49

In an athletic composition, the probability that an athlete wins a 100m race is

\frac{1}{8}

and the probability that he wins in high jump is

\frac{1}{4}

. What is the probability that he wins only one of the events?

$\frac{3}{32}$
$\frac{7}{3}$
$\frac{5}{3}$
$\frac{5}{16}$

Solution:

Pr. (winning 100m race) =

\frac{1}{8}

Pr. (losing 100m race) = 1 -

\frac{1}{8}

=

\frac{7}{8}

Pr. (winning high jump) =

\frac{1}{4}

Pr. (losing high jump ) = 1 -

\frac{1}{4}

=

\frac{3}{4}

Pr. (winning only one) = Pr. (Winning 100m race and losing high jump) or Pr.(Losing 100m race and winning high jump)

= (

\frac{1}{8} \times \frac{3}{4}

) + (

\frac{7}{8} \times \frac{1}{4}

)

=

\frac{3}{32} + \frac{7}{32}

=

\frac{10}{32}

=

\frac{5}{16}

© africaexams.com

Go to Question:

Prev Question

Next Question