Percent problems and financial mathematics

1003083306

Level: 
C
In a certain school, grades are given according to the rules listed below: \[\begin{array}{|c|c|} \hline \text{The percentage of the points gained} & \text{grade} \\\hline 0\%\text{ to } 49\% & 1 \\\hline 50\% \text{ to } 59\% & 2 \\\hline 60\% \text{ to } 79\% & 3 \\\hline 80\% \text{ to } 89\% & 4 \\\hline 90\% \text{ to } 94\% & 5 \\\hline 95\% \text{ to } 100\% & 6 \\\hline \end{array}\] Krysia gained \( 39 \) points from the history test. There were only \( 2 \) percentage points missing for her to get grade \( 4 \). What was the total amount of points one could get from the test?
\( 50 \) points
\( 41 \) points
\( 45 \) points
\( 55 \) points

1003083304

Level: 
C
The initial price of a certain number of ice bags was \( 24.20 \) zlotys. Now, you can buy \( 22 \) ice bags (which is \( 10\% \) more bags than before) for the same price. What is the percentage decrease in the price of one ice bag?
by app. \( 9\% \)
by app. \( 8\% \)
by \( 10\% \)
by \( 2.2\% \)

1003082209

Level: 
B
Two circles are given. The radius of the first circle is by \( 30\% \) longer than the radius of the other circle. It means that the area of the first circle is bigger than the area of the second one
by more than \( 60\% \).
by less than \( 50\% \), but more than \( 40\% \).
by less than \( 60\% \), but more than \( 50\% \).
by exactly \( 60\% \).

1003082207

Level: 
B
The angle \( \beta \) is by \( 25\% \) less than the angle \( \gamma \) and by \( 50\% \) greater than the angle \( \alpha \). The angle \( \gamma \) is
by \( 100\% \) greater than \( \alpha \).
by \( 50\% \) greater than \( \alpha \).
by \( 75\% \) greater than \( \alpha \).
by \( 25\% \) greater than \( \alpha \).

1003082206

Level: 
B
The price of the book was increased by \( 4.5 \) złotys which is \( 15\% \) of the initial price. Then it was increased by another \( 1.5 \) złotys. By how many percent did the overall price of the book increase?
by \( 20\% \)
by \( 6 \) złotys
by \( 25\% \)
by \( 16\% \)