The easiest examples
- Three cats
If three cats eat three mice in three minutes, after which time 140 cats eat 140 mice?
Is the number 109433 divisible by 7?
Charlie bought 7 same chocolates for 14 Eur. How many euros he pay for 27 chocolates?
- One half
One half of ? is: ?
What is better for people (employees)? ?
The parents had 2 daughters. Each of them had one brother. How many members family had?
One brick is 2 kg and half a brick heavy. What is the weight of one brick?
5 trees in 3 lines grows in the orchard. How many trees are in the orchard?
I have 12 balls and my friend has 18. About how many has my friend more balls?
A cyclist passes 88 km in 4 hours. How many kilometers he pass in 8 hours?
Compare fractions ?. Which fraction of the lower?
From which law follows directly the validity of Pythagoras' theorem in the right triangle? ?
- Is right?
Is triangle with sides 24, 51 and 45 right triangle?
- Proof PT
Can you easy prove Pythagoras theorem using Euclidean theorems? If so, do it.
- Reverse Pythagorean theorem
Given are lengths of the sides of the triangles. Decide which one is rectangular: Δ ABC: 73 m, 66 m, 51 m ? Δ DEF: 63 cm, 105 cm, 84 cm ? Δ GHI: 50 dm, 48 dm, 14 dm ? Δ JKL: 31 m, 45 m, 40 m ? Δ MNO: 28 m, 53 m, 45 m ?
Compare with characters >, <, =: 63.79 ? 63.79
Calculate how many hours take holidays, if take 1 weeks.
- 7 heroes
5 heroes galloping on 5 horses behind. How many ways can sort them behind?
The root of the equation ? is: ?
In how many ways can 7 shuttle vans line up at the airport?