2010006403
Level:
C
Find the number \( x \) if \( 40\% \) of its half is \( 70\% \) of the number \( x -3\).
\( 4\frac15 \)
\( 5\frac14 \)
\( 5 \)
\( 5\frac25 \)
Percent problems
2010006402
Level:
C
One third of a number \( a \) is by \( 75\% \) greater than one seventh of a number \( b \). Choose the true statement.
The number \(a\) is by \(25\%\) smaller than \(b\).
The number \(a\) is by \(75\%\) smaller than \(b\).
The number \(a\) is by \(400\%\) greater than \(b\).
The number \(a\) is by \(75\%\) greater than \(b\).
2010006401
Level:
C
Of the school's \(300\) pupils, \(67\%\) attend the sports club and \(42\%\) attend the music club. \(18\%\) attend both clubs. How many children do not attend any club?
\(27\) children
\(81\) children
\(87\) children
\(30\) children
2010006209
Level:
B
The angle \( \beta \) is by \( 20\% \) smaller than the angle \( \gamma \) and by \( 100\% \) greater than the angle \( \alpha \). The angle \( \alpha \) is
by \( 60\% \) smaller than \( \gamma \).
by \( 40\% \) smaller than \( \gamma \).
by \( 20\% \) smaller than \( \gamma \).
by \( 80\% \) smaller than \( \gamma \).
2010006208
Level:
B
There are \(14\) right-handed and \(18\) left-handed children among the children attending the ceramic group. Find the difference between percentages of right-handers and left-handers in the group. (Round the result to one decimal place.)
differ by \(27.3\, \%\)
differ by \(63.6\, \%\)
differ by \(36.4\, \%\)
differ by \(57.1\, \%\)
2010006207
Level:
B
If we increase an unknown number \(x\)
by \(8\, \%\), we
get \(432\).
Find \(x\).
\(400\)
\(466.56\)
\(397.44\)
\(380\)
2010006206
Level:
B
Find the number by \( 2.5{\small{{}^\text{o}\mkern-5mu/\mkern-3mu_\text{oo}}} \) greater than \( 800 \).
\(802\)
\(820\)
\(800.2\)
\(800.025\)
2010006205
Level:
B
The price of oil rose by \(60\%\). By how many percent it is necessary to reduce the price of oil so that it costs the same as before?
by \( 37.5\% \)
by \( 60\% \)
by \( 40\% \)
by \( 160\% \)
2010006204
Level:
B
The number of permanent residents of a city has decreased by \( 10\% \) per year in the last three years. How many residents did the city have three years ago, if we know that the last year the population was \(972\)?
\( 1\,200 \)
\( 1\,080 \)
\( 900 \)
\( 1\,070 \)
2010006203
Level:
B
Two sides of a rectangle were increased by \( 10\% \). What is the percentage change of the area of the rectangle?
it increased by \( 21\% \)
it increased by \( 20\% \)
it decreased by \( 40\% \)
it decreased by \( 20\% \)