Question

There are $5$ red, $2$ yellow and $3$ white roses in a flowerpot. One rose is selected from it at random. What is the probability that the selected rose is (1) red (2) yellow (3) not white colour?

Answer 1

Total number of roses in the flower pot $=5+3+2=10$
$\therefore$ Number of possible outcomes to select a rose at random is $10$.
(i) Let '$A$' be the event that the selected rose is of red colour.
No. of red roses in the flower pot $=5$
$\therefore P\left(A\right)=\frac{5}{10}=0.5$
(ii) Let '$B$' be the event that the selected rose of of yellow colour.
No. of yellow roses in the flower pot $=2$
$\therefore P\left(B\right)=\frac{2}{10}=0.2$
(iii) Let $C$ be the event when the selected rose is white in colour.

Then, $\overline{C}$ is the event when the selected rose is not of white colour.
No. of white roses in the flower pot $=3$
$\therefore P\left(C\right)=\frac{3}{10}=0.3$

Now, $P\left(\overline{C}\right)=1-P\left(C\right)=1-0.3=0.7$