probability question
please solve the following questions
Q1. A box contains 6 red balls, 7 green balls and 5 blue balls. Each ball is of a different size. The probability that the red ball selected is the smallest red ball is:
a. 1/18
b. 1/3
c. 1/6
d. 2/3
Q2. There are 50 ten paise coins placed on a table. Six of these shows tails and four shows heads. A coin is chosen at random and fliped(not tossed). This operation is performed seven times. One of these coins is then covered. Of the remaining nine conins, five shows tails and four shows heads. The covered coin shows
a. A head
b. A tail
c. More likely a head
d. More likely a tail
1. P(a red ball is selected
1. P(a red ball is selected )* P(red is the smallest red ) = 1/18.
or another way : there is only one "smallest red" and selecting that is only one on the first try.