# timers Q - need help

• May 24th 2006, 09:00 PM
aptiva
timers Q - need help
can anyone help me with this quesiton pleasee :)

The technical support group for the 1992 Winter games has ten electronic timers that can be used for five events. The events are run concurrently at different sites. Three of the events each require only one timer, but the other two each require two timers. One of the ten timers has a malfunction that makes it inaccurate.

a) What is the probability that timing is inaccurate in one of the events requiring two timers? 0.40
• May 24th 2006, 09:22 PM
earboth
Quote:

Originally Posted by aptiva
can anyone help me with this quesiton pleasee :)
The technical support group for the 1992 Winter games has ten electronic timers that can be used for five events. The events are run concurrently at different sites. Three of the events each require only one timer, but the other two each require two timers. One of the ten timers has a malfunction that makes it inaccurate.
a) What is the probability that timing is inaccurate in one of the events requiring two timers? 0.40

Hello,

you deal with binomial distribution. The probability to use an inaccurate timer is 0.1. So

$P(X=1)={10\choose 1} \cdot \left({1\over 10}\right) \cdot \left({9\over 10}\right)^9 \approx .3874$

Greetings

EB