Question 71

Mathematics Probability Hard

If a number x is selected at random from natural numbers 1,2,…,100, then the probability for \(x+\frac{100}{x}{\gt}29\) is

(A) \(\frac{37}{50}\)
(B) \(\frac{39}{50}\)
(C) \(\frac{41}{50}\)
(D) \(\frac{43}{50}\)
View Dynamic Solution & Explanation
Correct Solution: Option B

Step-by-step Solution:

Given that: \[ x + \frac{100}{x} > 29 \Rightarrow x^2 - 29x + 100 > 0 \] This simplifies to: \[ (x - 4)(x - 25) > 0 \] Solving this inequality: \[ x > 25 \quad \text{or} \quad x < 4 \] Thus, \( x \) can take a total of 78 values (1, 2, 3, 26, ..., 100). The required probability is: \[ \frac{78}{100} = \frac{39}{50} \]