A

9000139507

Level: 
A
The average mass of five melons is \(2\: 400\, \mathrm{g}\). We have to add another melon such that the new average value of all six melons will be \(2\: 420\, \mathrm{g}\). Find the mass of the sixth melon.
\(2\: 520\, \mathrm{g}\)
\(2\: 540\, \mathrm{g}\)
\(2\: 480\, \mathrm{g}\)
\(2\: 460\, \mathrm{g}\)

9000139501

Level: 
A
Ten apples in a box have average mass \(200\, \mathrm{g}\). We remove one apple of the mass \(200\, \mathrm{g}\) from the box. What is the change in the average mass of the apples from the box?
The average mass of the apples does not change.
The average mass of the apples decreases by \(20\, \mathrm{g}\).
The average mass of the apples increases by \(20\, \mathrm{g}\).
There is not enough information to solve this problem.

9000139305

Level: 
A
There are five rooms with three beds and one room with five beds in a hotel. A group of \(20\) people booked rooms at this hotel. Determine the number of possible choices for the people to the five-bed room.
\(\frac{20!} {5!\, 15!}=15\:504\)
\(20\cdot 3\cdot 5=300\)
\(\frac{20!} {3!\, 5!}=3\:379\:030\:566\:912\:000\)
\(20^{5}=3\:200\:000\)

9000139504

Level: 
A
The average salary of five employees is \(3\: 000\, \mathrm{Euro}\). This group of the employees is expanded by one new person. The salary of the new person is \(2\: 400\, \mathrm{Euro}\). Find the change in the average salary of this group.
The average salary decreases by \(100\, \mathrm{Euro}\).
The average salary decreases by \(480\, \mathrm{Euro}\).
The average salary increases by \(400\, \mathrm{Euro}\).
The average salary increases by \(480\, \mathrm{Euro}\).

9000139506

Level: 
A
There are eight mandarins of average mass \(90\, \mathrm{g}\) in the box. We got two another mandarins and add them to the box. The new average mass of the mandarins in the box is \(92\, \mathrm{g}\). Find the average mass of the two added mandarins.
\(100\, \mathrm{g}\)
\(92\, \mathrm{g}\)
\(96\, \mathrm{g}\)
\(106\, \mathrm{g}\)

9000139309

Level: 
A
There are \(20\) tablets in an e-shop. From this amount \(18\) tablets are new and \(2\) tablets have been returned by customers. The e-shop manager gets an order containing three tablets and he wants to get rid of the returned tablets first. How many possibilities exist to complete the order?
\(18\)
\(\frac{18!} {3!\, 15!}=816\)
\(18\cdot 16\cdot 3=864\)
\(20\cdot 19\cdot 18=6\:840\)

9000139310

Level: 
A
There are \(20\) tablets in an e-shop. From this amount \(18\) tablets are new and \(2\) tablets have been returned by customers. The e-shop manager gets an order containing three tablets and he wants to use only the new tablets for this order. How many possibilities exist to complete the order?
\(\frac{18!} {3!\, 15!}\)
\(18\)
\(18\cdot 16\cdot 3\)
\(20\cdot 19\cdot 18\)