Тиширай краше ецје мивії лацце kun la ci kiš 15 zakunukuki нуцциа акацфа на писисцили Бимацт іміні 2. уа кии зи зима аклс на сочицda kunu ncuamuыse puцита авонана шимцзакис вцбишщ зр ітцньц 4 пуцита италиуа ццццкишда сцзіц сцтсздан цннцичд.

Cost price = 15,000
Selling price = 20,000

The profit made by the merchant is $\boxed{\text{5,000}}$.

Question 2:
"2. Umucuruzi yaguze imyenda hafi y'ibihumbi 21. Yagurishije imyenda yose ku giciro cy'ibihumbi 25.
a. Ese uyu mucuruzi yabonye inyungu ingana iki?
b. Ese uyu mucuruzi azasigara abana bangahe niba yari asanzwe afite 3?"

Translation: A merchant bought clothes for approximately 21,000. He sold all the clothes for 25,000.
a. How much profit did this merchant make?
b. How many children will this merchant have left if he originally had 3?

a) To find the profit, we subtract the cost price from the selling price.

Cost price = 21,000
Selling price = 25,000

The profit made by the merchant is $\boxed{\text{4,000}}$.

b) This part of the question is about the merchant's children and is unrelated to the financial transaction. There is no information to suggest the number of children would change.
The number of children remains $\boxed{\text{3}}$.

Question 3:
"3. Ufite 15/16. Ese ni angahe adashobora kuba pusa na 8/9?"
Below this, there are options:
"a. Ubwishimwe bwawe --" (Your happiness --)
"b. Mu gihe kirenga 8/9" (More than 8/9)
"c. 4/4"
"d. 7/7"
"e. Ubusa" (Zero)
"f. 1/2"

Translation: You have $\frac{15}{16}$. How much is it that cannot be equal to $\frac{8}{9}$?

The phrase "ni angahe" (how much) usually asks for a numerical quantity. However, given the options, especially option 'b' which is a comparative statement, the question is likely asking for a comparison between the two fractions.

To compare them, we can find a common denominator or cross-multiply.

Cross-multiply the numerators by the opposite denominators:

Since $135 > 128$, it means that $\frac{15}{16} > \frac{8}{9}$.
Therefore, $\frac{15}{16}$ is greater than $\frac{8}{9}$.

Option b states "Mu gihe kirenga 8/9", which translates to "More than 8/9". This accurately describes that $\frac{15}{16}$ is greater than $\frac{8}{9}$.

The correct option is $\boxed{\text{b. Mu gihe kirenga 8/9}}$.