A die is thrown three times. If the first throw is a five, the probability of getting 14 as the sum is |
$\frac{1}{9}$ $\frac{1}{18}$ $\frac{1}{36}$ $\frac{1}{54}$ |
$\frac{1}{9}$ |
The correct answer is Option (1) → $\frac{1}{9}$ Given that the first throw is $5$. To get total sum $14$, the sum of the second and third throws must be $14-5=9$ Possible ordered pairs $(x,y)$ such that $x+y=9$ where $x,y\in\{1,2,3,4,5,6\}$ are $(3,6),(4,5),(5,4),(6,3)$ Total possible outcomes for second and third throws $=6\times6=36$ Favourable outcomes $=4$ Probability $=\frac{4}{36}$ $=\frac{1}{9}$ |