A) \[\frac{1}{8}\]
B) \[\frac{1}{5}\]
C) \[\frac{1}{24}\]
D) \[\frac{1}{6}\]
Correct Answer: B
Solution :
Key Idea: The number having unit digit 0 or 5 will be divisible by 5. All the numbers divisible by IS are also divisible by 5. In first 120 natural numbers total number of multiple of 5,\[n(A)=24\]and total number of multiple of 15,\[n(B)=8\]and\[n(A\cap B)=8\]. \[\therefore \] \[n(A\cup B)=n(A)+n(B)-n(A\cap B)\] \[=24+8-8=24\] \[\therefore \]Required probability\[=\frac{24}{120}=\frac{1}{5}\]You need to login to perform this action.
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