Out of first 20 natural numbers, one number is selected at random. The probability that it is either an even number or a prime number is -
A. $$\frac{{1}}{{2}}$$
B. $$\frac{{16}}{{19}}$$
C. $$\frac{{4}}{{5}}$$
D. $$\frac{{17}}{{20}}$$
Answer: Option D
Solution(By Examveda Team)
$$\eqalign{ & n\left( S \right) = 20 \cr & n\left( {{\text{Even no}}} \right) = 10 = n\left( E \right) \cr & n\left( {{\text{Prime no}}} \right) = 8 = n\left( P \right) \cr & P\left( {E \cup P} \right) = \frac{{10}}{{20}} + \frac{8}{{20}} - \frac{1}{{20}} \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \frac{{17}}{{20}} \cr} $$Related Questions on Probability
A. $$\frac{{1}}{{2}}$$
B. $$\frac{{2}}{{5}}$$
C. $$\frac{{8}}{{15}}$$
D. $$\frac{{9}}{{20}}$$
A. $$\frac{{10}}{{21}}$$
B. $$\frac{{11}}{{21}}$$
C. $$\frac{{2}}{{7}}$$
D. $$\frac{{5}}{{7}}$$
A. $$\frac{{1}}{{3}}$$
B. $$\frac{{3}}{{4}}$$
C. $$\frac{{7}}{{19}}$$
D. $$\frac{{8}}{{21}}$$
E. $$\frac{{9}}{{21}}$$
What is the probability of getting a sum 9 from two throws of a dice?
A. $$\frac{{1}}{{6}}$$
B. $$\frac{{1}}{{8}}$$
C. $$\frac{{1}}{{9}}$$
D. $$\frac{{1}}{{12}}$$
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