Percent problems and financial mathematics

9000078905

Level: 
B
A new laptop has been introduced to the marked with the original price \(\$1\: 090\). Soon after the introduction the price has been increased temporarily by \(20\, \%\) and after several months decreased by \(30\, \%\). Find the final price for the laptop. Round your result to the nearest integer.
\(\$916\)
\(\$981\)
\(\$952\)
\(\$930\)

9000078908

Level: 
B
A house price in the March was \(\$259\: 000\). The house has not been sold for several months and the price dropped to \(\$234\: 000\) in August. Write the discount as percents of the original price. (Round to the tenth.)
\(9.7\, \%\)
\(10.7\, \%\)
\(10.5\, \%\)
\(9.5\, \%\)

9000085301

Level: 
B
A bike was introduced to the market with the initial price \(\$10\: 000\) in April. As a consequence of bad sales values, the price has been decreased by \(20\, \%\) in June and by another \(20\, \%\) in September. Find the price in September.
\(\$6\: 400\)
\(\$6\: 000\)
\(\$6\: 125\)
\(\$6\: 500\)

9000085302

Level: 
B
There are \(32\) students in the class (\(20\) boys and \(12\) girls). One quarter of the boys and one quarter of the girls are excellent students. Suppose that one boy and one girl, both excellent students, move to another school. Find the difference in the ratio of excellent students in the class before and after the change in the class.
\(5\, \%\)
\(6.25\, \%\)
\(7.5\, \%\)
\(8.25\, \%\)

9000085303

Level: 
B
The shop received \(30\) pieces of TV from the manufacturer NoName. Five TVs in this delivery were defect. The shop also received TVs from the manufacturer GoodName. All these TVs were perfect. The final inspection revealed that \(10\, \%\) of TVs were defect in total. Use these information to find out how many TVs have been supplied from the producer GoodName.
\(20\)
\(25\)
\(18\)
\(16\)

9000085304

Level: 
B
The final score of the hockey match between teams \(A\) and \(B\) was \(2 : 2\). The goaltender of \(A\) had success rate \(90\, \%\) (he stopped \(90\, \%\) of all shots on goal) and the goaltender of the team \(B\) had fail rate \(20\, \%\) (\(20\, \%\) of all shots on goal went into his net). How many shots on goal has been in the match in total?
\(30\)
\(25\)
\(35\)
\(40\)

9000085305

Level: 
B
The price for the first issue of the book was \(\$100\), the price for the second issue \(\$125\). Find the rate of sale of the second issue if the target price for the second issue is the same as for the first issue.
\(20\, \%\)
\(22.5\, \%\)
\(17.5\, \%\)
\(25\, \%\)