C

9000009304

Level: 
C
A tank contains \(1\: 000\) litres of petrol. The petrol escapes at a constant speed \(20\) litres per minute. In what time will there be just \(200\) litres of the petrol in the tank?
\(40\, \mathrm{min}\)
\(10\, \mathrm{min}\)
\(20\, \mathrm{min}\)
\(30\, \mathrm{min}\)

9000009305

Level: 
C
Anne decided to make a bicycle trip with his friend which lives \(10\, \mathrm{km}\) from Anne house. Anne went from her house to the house of her friend first. Then they started to measure the time and went on a constant velocity \(18\, \mathrm{km}/\mathrm{h}\). In what time will be the total distance traveled by Anne equal to \(34\, \mathrm{km}\)?
\(1\, \mathrm{h}\) \(20\, \mathrm{min}\)
\(1\, \mathrm{h}\) \(58\, \mathrm{min}\)
\(2\, \mathrm{h}\) \(26\, \mathrm{min}\)
\(2\, \mathrm{h}\) \(30\, \mathrm{min}\)

9000009306

Level: 
C
Anne decided to make a bicycle trip with his friend which lives \(10\, \mathrm{km}\) from Anne house. Anne went from her house to the house of her friend first. Then they started to measure the time and went on a constant velocity \(18\, \mathrm{km}/\mathrm{h}\) for \(2\, \mathrm{h}\) \(10\, \mathrm{min}\). What is the total distance traveled by Anne?
\(49\, \mathrm{km}\)
\(39\, \mathrm{km}\)
\(35\, \mathrm{km}\)
\(45\, \mathrm{km}\)

9000009307

Level: 
C
The sound velocity at the temperature \(0\, ^{\circ } \mathrm{C}\) is \(331\, \mathrm{m}/\mathrm{s}\). An increase of the temperature by \(1\, ^{\circ } \mathrm{C}\) increases the speed of velocity by \(0.6\, \mathrm{m}/\mathrm{s}\). Estimate the sound speed at the temperature \(18\, ^{\circ } \mathrm{C}\).
\(341.8\, \mathrm{m}/\mathrm{s}\)
\(341.2\, \mathrm{m}/\mathrm{s}\)
\(348\, \mathrm{m}/\mathrm{s}\)
\(349\, \mathrm{m}/\mathrm{s}\)

9000009309

Level: 
C
The speed of a swimmer in a \(50\, \mathrm{m}\)-pool is \(0.8\, \mathrm{m}/\mathrm{s}\). How fast will he swim two pool lengths (one pool length is \(50\) meters), if he/she needs \(2\, \mathrm{s}\) to turn at the end of the pool?
\(127\, \mathrm{s}\)
\(82\, \mathrm{s}\)
\(84\, \mathrm{s}\)
\(129\, \mathrm{s}\)

9000009311

Level: 
C
The graph shows the speed of a train as a function of time. Find an analytic expression for this function.
\(v = 30 - \frac{3}{4}t,\ t\in [ 0;20] \)
\(v = 30 + \frac{3}{4}t,\ t\in [ 0;20] \)
\(v = 15 +\frac{3}{4}t,\ t\in [ 0;20] \)
\(v = 30 - \frac{4}{3}t,\ t\in [ 0;20] \)

9000009906

Level: 
C
Consider a function \[ f(x) = \frac{k} {x} \] with a nonzero real parameter \(k\). Describe what happens with the function \(f\) if the coefficient \(k\) changes the sign.
The function changes the type of monotonicity on the sets \(\mathbb{R}^{+}\) and \(\mathbb{R}^{-}\) (either from an increasing function into a decreasing function or vice versa).
The function changes its parity (from an odd function into an even function or from an even function into an odd function).
The domain of the function changes.
None of the above, both functions have the same parity, monotonicity and domain.