Question

If a black bag contains 100 casino chips with values €5, €10, €15, €20, €50. There are ten chips of value €5. You have to withdraw one chip from the box. What is the probability that it has a value more than €5?

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

We have to find the probability of withdrawing a chip of value more than €5. i.e., either €10 or €15 or €20 or €50. In short, we have to find the probability of the first chip not being €5.
P (chip other than €5 or not €5) = 1 - P( €5 chip)
Probability of an event, P(E) = $\frac{numberoffavourableoutcomes}{totalnumberofoutcomes}$
$\Rightarrow$ P( €5 chip) = $\frac{numberof€5chip}{totalnumberofchip}$ = $\frac{10}{100}$ = $\frac{1}{10}$
P(non €5 chip)= P(chip having more value than €5) = 1 - $\frac{1}{10}$ = $\frac{9}{10}$

Therefore, the probability that the chip has a value more than €5 is $\frac{9}{10}$.