Linear equations and inequalities

1003029706

Level: 
C
In a river, water flows at speed of 1mps. A boat, which moves at speed of 4mps in a calm water, carries mail to a little town distant 6km downstream. How long will it take till the boat returns? (We disregard the time necessary for mail-handover.) Note: Abbreviation "mps" stands for meter per second.
53min 20s
50min
3min 12s
1min 20s

1003031101

Level: 
C
So far Johnny has received the grades: 5, 3, 3, 3, 2, 2, 1, 1, for the math course in this school term. What another grade he needs to get so that the average of grades is lower than 2.5? (Assumption: All grades are of the same weight in grading scale of 1, 2, 3, 4, 5, where 1 is the best result.)
at worst 2
at worst 3
only 1
The arithmetic mean can’t be less than 2.5 in any case.

1003031103

Level: 
C
Five litres of a quality wine in by yourself provided bottles cost more than three and a half litres of the same wine in a bigger wine container. The container price is 150CZK. Complete the next statement so that it is true. The price of one litre of this quality wine is
greater than 100CZK.
less than 100CZK.
greater than 350CZK.
greater than 500CZK.

1003031104

Level: 
C
Dan and Jane took a bike trip. Dan rode for 3 hours at constant speed. Jane rode for half an hour longer at the speed of 4kph less than Dan’s speed. Identify, which of the following statements about Dan’s speed is true.
The speed is less than 28kph.
The speed is greater than 28kph.
The speed is less than 20kph.
The speed is greater than 24kph.

1003197402

Level: 
C
Paul rides the bike at a constant speed of 18kph. Eighteen minutes after Paul starts his trip, Tom takes the same route on a motorbike at an average speed of 40kph. How far behind Paul will Tom be after 12 minutes of his ride?
1km
60km
14km
after 12 minutes of ride Tom will be in front of Paul

1003197404

Level: 
C
The stock of the monitored company lost 12% of its value during a week. Its fall continued over the next week, and the value declined by another 4%. Let’s denote the original value of the stock by an x. From the following possibilities, choose the expression that gives the value of the stock at the end of the monitored term.
0.96⋅0.88x
(0.96+0.88)x
0.04⋅0.12x
[1−(0.04+0.12)]x

1003197405

Level: 
C
Nine people travel by bus. The same number of people gets off the bus at each of three bus stops and then so many people get in to double the number of remaining bus passengers. After the third bus stop there are 30 people in the bus. How many passengers get off at each bus stop?
3
2
1
6

1003197406

Level: 
C
Each of two companies should deliver the same amount of raw material. While inspecting it was found out that the company A delivered 150kg and the company B delivered 194kg. At the moment of inspection, company A has to deliver yet three times more than what is left to be delivered by company B. Choose the equation which does NOT correspond to the described situation.
3(x−150)=x−194, where x represents the total planned delivery of both companies.
x−150=3(x−194), where x represents the total planned delivery of both companies.
150+3x=194+x, where x represents the amount of raw material which is left to be delivered by company B.
150+x=194+x3, where x represents the amount of raw material which is left to be delivered by company A.