The probability that in the toss of two dice, we obtain the sum 7 or 11 is

Options

A. `(1)/(6)`
B. `(1)/(18)`
C. `(2)/(9)`
D. `(23)/(108)`

Answer

C

Explanation

`because n(S) = 36`
Let E = Event of getting sum 7
`= {(1,6), (2,5), (3,4), (4,3), (4,3),(5,2), (6,2)}`
`therefore n(E ) = 6 rArr F` = Event of getting sum `11 = {(6,5),(5,6)}`
`therefore n(F)=2`
Also, `" " n(E nn F)=0`
`therefore " " n(E uu F) = n(E )+n(F)-n(E nn F)`
`= 6+2=8`
`therefore` Required probability `=(8)/(36)=(2)/(9)`