**Question 1:**
How many four-digit numbers can you get out of $\text{\hspace{0.17em}}0,\text{\hspace{0.17em}}3,\text{\hspace{0.17em}}7,\text{\hspace{0.17em}}8\text{\hspace{0.17em}}$
?

**Question 2:**
There are $\text{\hspace{0.17em}}19\text{\hspace{0.17em}}$
balls in the box: $\text{\hspace{0.17em}}10\text{\hspace{0.17em}}$
of red ones and $\text{\hspace{0.17em}}9\text{\hspace{0.17em}}$
of blue ones. In how many ways can two balls of the same color be picked?

**Question 3:**
In how many ways can you pick a captain and his deputy in a group of $\text{\hspace{0.17em}}23\text{\hspace{0.17em}}$
soldiers?

**Question 4:**
John has $\text{\hspace{0.17em}}4\text{\hspace{0.17em}}$
cats. In how many ways he can take $\text{\hspace{0.17em}}2\text{\hspace{0.17em}}$
of them in his hands (one - in left hand, another - in right)?

**Question 5:**
Three passengers walk into the elevator of the $\text{\hspace{0.17em}}11$-floor building (ground floor is not included). In how many ways all three passengers can get out on different floors?

**Question 6:**
From the box in which there are $\text{\hspace{0.17em}}10\text{\hspace{0.17em}}$
white, $\text{\hspace{0.17em}}4\text{\hspace{0.17em}}$
red and $\text{\hspace{0.17em}}5\text{\hspace{0.17em}}$
green balls, are randomly picked $\text{\hspace{0.17em}}3\text{\hspace{0.17em}}$
. What is the probability that all three of them would be white?

**Question 7:**
The situation is the same as in the previous task. What is the probability of picking one white, one red and one green ball?

**Question 8:**
At the language school people can only study French, German or both. The event $\text{\hspace{0.17em}}A\text{\hspace{0.17em}}$
happens when a random student decides to study French, the event $\text{\hspace{0.17em}}B\text{\hspace{0.17em}}$
- when decides to study German. What is the probability when a randomly picked student decides to learn both languages(Event $\text{\hspace{0.17em}}A\cap B\text{\hspace{0.17em}}$
), if $\text{\hspace{0.17em}}P\left(A\right)=\frac{3}{4},P\left(B\right)=\frac{2}{5}\text{\hspace{0.17em}}$
?

**Question 9:**
There are $\text{\hspace{0.17em}}2$ red and $\text{\hspace{0.17em}}4\text{\hspace{0.17em}}$
blue balls in the box. Event $\text{\hspace{0.17em}}A\text{\hspace{0.17em}}$
happens when the first randomly picked ball is red. Event $\text{\hspace{0.17em}}B\text{\hspace{0.17em}}$
happens when second randomly picked ball is also red. Calculate $\text{\hspace{0.17em}}{P}_{A}\left(B\right)\text{\hspace{0.17em}}$
.

**Question 10:**
An archer hits the target with the probability $\text{\hspace{0.17em}}0.9\text{\hspace{0.17em}}$.
What is the probability that out of three shots he hits the target only the third time?