All Tasks
Subtraction
Which fraction should we add to $\dfrac{3}{8}$ to find the result $\dfrac{5}{9}$?
# Fractions
Training
6
Getting to know Average
Calculate the average of the following 4 numbers: 9 / 10 / 2 / 3.
# Mean & median
Learning
4
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