All Tasks

Farmer Production

One farmer sold to four dealers the $\dfrac{2}{5}$, $\dfrac{2}{15}$, $\dfrac{1}{3}$ and $\dfrac{1}{10}$ of his production. How much of the production was not sold?
 
# Fractions

Training
6

Cyclists average weight

A group of 8 cyclist is composed by 2 women and 6 men. The average weight of the 8 cyclist is 80 kg. The average of men weight is 88 kg. Calculate how much is the average weight of women.
 
# Mean & median

Reasoning
8

Joseph rating problem

Joseph in the last 7 tests takes the following grades: 7.5 / 8 / 5.5 / 4 / 5.5 / 6 / 6.5. How much is his average rating? (round to the second decimal digit)
 
# Mean & median

Training
6

Faucets

A faucet fills up a tank in 10 minutes. Another faucet fills up the same tank in 15 minutes. How many minutes does it take for the tank to be full if we open the two faucets together?
 
# Fractions

Modeling
6

Sibling Survey

The 24 students in a class conducted a survey on the number of siblings every student has. On average, a student in this class has about 1,83 siblings. The number of students with 1 and 2 siblings is equal. Exactly 6 Students in the class have more than 2 siblings. Below, select the diagrams from the title image, that represent the collected data correctly.
 
# Standard diagrams

Training
7

Playing with cards and probabilities

A certain set of playing cards is made of twelve red cards and some black cards. A card is chosen at random from this set. It is known that the probability of that card being red is 75%. How many black cards are there in this set?
 
# One-stage random experiments

Reasoning
8