There are 20 cards. Ten of these cards have the letter `"I"` printed on them and the other 10 have the letter `"I"` printed on them. If three cards picked up at random and kept in the same order, the probability of making word IIT is `1//9,1//3` b. `1//16 ,1//4` c. `1//4,1//2` d. none of these

Options

A. `4//27`
B. `5//38`
C. `1//8`
D. `9//80`

Answer

B

Explanation

Consider the following events :
A: getting a card with mark I in first draw
B: getting a card with marks I in second draw
C: getting a card with mark T in this draw
Then, the required probability is
`P(AnnBnnC)=P(A)P(B//a)P(C//AnnB)`
`=10/20xx9/19xx10/18=5/38`