Answer:
The probability of taking $ 2.5 is 12.2%
Step-by-step explanation:
To make $ 2.5 with only 3 coins, you have to take out 2 $ 1 coins and a $ 0.5 coin in one of the following 3 ways:
(1) (1) (0.5) = (2.5) (i)
(1) (0.5) (1) = (2.5) (ii)
(0.5) (1) (1) = 2.5 (iii)
There are 3 coins (1)
There are 9 coins (0.5)
Therefore, the probability of drawing a coin from (1) on the first attempt is 3/12
The probability of drawing a coin of (0.5) on the first attempt is 9/12.
Then, the probability of drawing $ 2.5 from the form (i) is:
[tex]P_{(i)}= \frac{3}{12}*\frac{2}{11}*\frac{9}{10} = 0.0409 = P_{(ii)} = P_{(iii)}[/tex]
Finally:
P ($ 2.5) = P (i) U P (ii) U P (iii)
P ($ 2.5) = P (i) + P (ii) + P (iii)
P ($ 2.5) = 3P (i)
P ($ 2.5) = 3 * 0.0409
P ($ 2.5) = 12,227
The probability of taking $ 2.5 is 12.2%
