GATE CSE 1996 | Question: 1.5

Question

Two dice are thrown simultaneously. The probability that at least one of them will have $6$ facing up is

• A. $\frac{1}{36}$

• B. $\frac{1}{3}$

• C. $\frac{25}{36}$

• D. $\frac{11}{36}$

Comments

Sample space  $=6*6 = 36$
Favorable cases $= (6,6), (6,1)(6,2)(6,3)(6,4)(6,5)(1,6)(2,6)(3,6)(4,6)(5,6)$
$=\frac{11}{36}$

Answer 1

Answer is (D)

$1- ($no. $6$ in both the dice $)=1-\left(\dfrac{5}{6} \times\dfrac{5}{6}\right)=\dfrac{11}{36}.$

Comments

@puja :unflag tthe answer, i have corrected it now !

---

I hav flagged it because that editor named pawan singh .... that may be his name ... he edited things wrongly in many questions and answers ...

---

wrong and edited

Answer 2

This question can be done simply as question is asking for at least one of them facing 6 ..

 

P(at least one 6 face up)= 1 - (none of them facing 6)

1 - ( 5/6 * 5/6)

1- 25/36

11/36..

Answer 3

P(atleast one of dice will have 6 facing)  = 1 - P(none of dice have 6 facing up)

                                                                = 1 - ( 5/6 * 5/6)

                                                                 =1- 25/36

                                                                  = 11/36