# The Probability of Guessing the Correct Answer to a Certain Test Questions is X 12 If the Probability of Not Guessing the Correct Answer to this Question is 2 3 Then X = - Mathematics

MCQ

The probability of guessing the correct answer to a certain test questions is$\frac{x}{12}$ If the probability of not  guessing the correct answer to this question is$\frac{ 2}{3}$ then x =

• 2

•  3

•  4

• 6

#### Solution

Probability of guessing a correct answer to a certain question is  x/12

Probability of not guessing a correct answer to a same question  2/3

TO FIND: The value of x

CALCULATIONWe know that sum of probability of occurrence of an event and probability of non occurrence of an event is 1.

If E is an event of occurrence and overlineE is its complementary then P(overlineE)+P(overline E)=1

According to the question we have

x/12+2/3=1

(x+8)/12=1

x+8=12

x=4

Is there an error in this question or solution?

#### APPEARS IN

RD Sharma Class 10 Maths
Chapter 16 Probability
Q 6 | Page 36