Question

The probability of getting sum more than 7 when a pair of dice are thrown is:

• A. $\frac{7}{36}$
• B. $\frac{5}{12}$
• C. $\frac{7}{12}$
• D. none of these

Answer 1

Answer: (B)

Here n (S) = $6^2$ = 36
Let E be the event "getting sum more than 7" i.e. sum of pair of dice = 8, 9, 10, 11, 12
i.e. $E=\left\{\begin{array}{ccccc}\left(2,6\right)& \left(3,5\right)& \left(4,4\right)& \left(5,3\right)& \left(6,2\right)\\ \left(3,6\right)& \left(4,5\right)& \left(5,4\right)& \left(6,3\right)& \\ \left(4,6\right)& \left(5,5\right)& \left(6,4\right)& & \\ \left(5,6\right)& \left(6,5\right)& \left(6,6\right)& & \end{array}\right\}$
$\therefore n(E)=15$
$\therefore$ Required prob $=\frac{n(E)}{n(S)}=\frac{15}{36}=\frac{5}{12}$