1003099404
Level:
B
The number \( 725233+x \) after dividing by \( 9 \) is to give a remainder of \( 5 \). Which of the given numbers shall we substitute for \( x \)?
\( 1 \)
\( 3 \)
\( 2 \)
\( 8 \)
Elementary arithmetics
1003099403
Level:
B
The number \( x \) when divided by \( 7 \) gives a remainder of \( 3 \). The number \( x \) can be written in the form:
\( 7n+3\text{, }n\in\mathbb{N} \)
\( 3n+7\text{, }n\in\mathbb{N} \)
\( 7(n+3)\text{, }n\in\mathbb{N} \)
\( 3(n+7)\text{, }n\in\mathbb{N} \)
1003099402
Level:
B
How many odd double-digit numbers give the reminder of \( 2 \) when divided by \( 9 \) and are divisible by \( 13 \) as well?
\( 1 \)
\( 2 \)
\( 3 \)
\( 4 \)
1003099401
Level:
B
The number \( 43256232a2 \) is divisible by \( 9 \) if
\( a= 7 \).
\( a= 1 \).
\( a= 0 \).
\( a= 4 \).
1003099206
Level:
A
Earth weighs \( 5.98\cdot10^{24}\,\mathrm{kg} \), the Moon weighs \( 7\cdot10^{22}\,\mathrm{kg} \). Calculate in kilograms the weight of both the Moon and Earth.
\( 6.05\cdot10^{24} \)
\( 6.05\cdot10^{22} \)
\( 1.298\cdot10^{24} \)
\( 12.98\cdot10^{24} \)
1003099205
Level:
A
Mass of a hydrogen atom is \( 0.000\,000\,000\,000\,000\,000\,000\,001\,67\,\mathrm{g} \). Give the mass in exponential notation.
\( 1.67\cdot10^{-24}\,\mathrm{g} \)
\( 167\cdot10^{-26}\,\mathrm{g} \)
\( 1.67\cdot10^{24}\,\mathrm{g} \)
\( 167\cdot10^{-21}\,\mathrm{g} \)
1003099204
Level:
A
Consider the information given in the table. Calculate the shortest distance between Neptune (the farthest planet from the Sun) and Mercury (the closest planet to the Sun).
\[
\begin{array}{|c|c|} \hline \text{Planet} & \text{Distance from the Sun } (\mathrm{km} ) \\\hline \text{Mercury} & 5.8\cdot10^7 \\\hline \text{Neptune} & 4.5\cdot10^9 \\\hline \end{array}
\]
\( 4.442\cdot10^9\,\mathrm{km} \)
\( 4.558\cdot10^9\,\mathrm{km} \)
\( 1.3\cdot10^7\,\mathrm{km} \)
\( 1.3\cdot10^9\,\mathrm{km} \)
1003099203
Level:
A
A man sleeps \( 8 \) hours a day on average. How many seconds on average does he sleep during the longest month of the year? Give the result in exponential notation.
\( 8.928\cdot10^5\,\mathrm{s} \)
\( 1.488\cdot10^4\,\mathrm{s} \)
\( 8928\cdot10^2\,\mathrm{s} \)
\( 8.64\cdot10^5\,\mathrm{s} \)
1003099202
Level:
A
The average distance from Mars to the Sun is \( 2.28\cdot10^8\,\mathrm{km} \). Give the distance in the standard form.
\( 228\,000\,000\,\mathrm{km} \)
\( 22\,800\,000\,\mathrm{km} \)
\( 2\,280\,000\,000\,\mathrm{km} \)
\( 22\,800\,000\,000\,\mathrm{km} \)
1003099201
Level:
A
A toe sometimes appears as a unit of energy in various publications. One toe is a unit of energy defined as the amount of energy released by burning one tonne of crude oil and it equals \( 41 868\,\mathrm{MJ} \) (\( 1 \,\mathrm{MJ} = 1\, 000\, 000 \,\mathrm{J} \)). How many joules are in \( 1 \) toe?
\( 4.1868\cdot10^{10} \)
\( 4.1868\cdot10^{8} \)
\( 4.1868\cdot10^{9} \)
\( 4.1868\cdot10^{11} \)