Question

A dice is thrown six times, it being known that each time a different digit is shown. The probability that a sum of $12$ will be obtained in the first three throws is

• A. $5/24$
• B. $25/216$
• C. $3/20$
• D. $1/12$

Answer 1

The correct option is C $3/20$

All outcomes are different so total number of possible outcome$=6\times 5\times 4=120$

Favourable outcomes are $(6,5,1)$ $(6,4,2)$ $(5,4,3)$ total is $3\times 3!=18$

Probability $=\frac{18}{120}=\frac{3}{20}$