Second math challenges
- Upload here your challenges, saying which group is the creator and to which group is addressed
- Answer the challenges in the forum (once all the members of the group have agreed on the answer), as a reply of the proposed challenge. Remember writing your names an the international group you belong to.
- Assess the challenge in the forum, also after agreed with your partners
Link to forum: https://school-education.ec.europa.eu/es/node/679402
Group 1 proposes:
- Despina Kal
- Spiros
- Bruno
- Aser
A teacher writes the digits shown on the board. He asks a student to write some multiplication signs between the digits so that the resulting expression is equal to 2023. How many multiplication signs should the student write?
1717171
Group 9 answers : Mara_Sandra_Xenophon_Anastasis
------------------------------------------------------------------------------------------------------------------
Group 2 proposes:
- Yaiza
- Lorena
- Marina
- Irene
How can you make this equation correct: 81 x 9 = 801?
Group 3 answers: Carla_Alba_Odysseus_Michalis
------------------------------------------------------------------------------------------------------------------
Group 3 proposes:
Carla-Alba-Odysseus-Michalis
Second Math Challenge:
We write the numbers for 1 to 9 in a random arrangement in order to shape a 9-digit natural number.
What is the probability this number to be multiple of 18?
Group 10 answers: Raquel_Eva_Marina_Angelo D_George_Despina K
-------------------------------------------------------------------------------------------------------------------
Group 4 proposes:
Sotiris
Myrto
Antia F.
Antia G.
My grandmother is very absent-minded. She forgot the password to her safe. She needs help to find the password.
She remembers that the password has 5 numbers, the first number is 8 (her wedding day) or 9 (her birthday); the second and fourth are the same and the third and fifth are odd.
How many combinations do I have to try to make sure that the password is correct?
Group 8 answers: Andros_Celia_Zoe_Max
------------------------------------------------------------------------------------------------------------------
Group 5 proposes:
Issidore
Angel
Sheila
Ismael
The watch riddle
While looking at my watch, I noticed that the minute hand was about to line up with the hour hand at about 14:10. So I wondered about the pointer alignments. At 12:00, as we know, the hour hand is covered by the minute hand, How many more times does this happen during the twelve hours, and at what time, to the nearest second, after 12:00 does the next alignment of the hands take place?
Group 4 answers: Antía F_Antía G_Sotiris_Myrto
------------------------------------------------------------------------------------------------------------------
Group 6 proposes:
Aggelos
Ilias
Martin
Michi
A number is written in each box of a 3 x 3 square. Unfortunately ink fell which covered the numbers. The sum of the three numbers in each of the first two columns and in each of the first two rows of the square is as shown in the picture below. The sum of the three numbers in the third column is A and the sum of the numbers in the third row is B. What is the value of A-B
A) 3 B) 6 C) 13 D) 21
Group 1 answers: Bruno_Aser_Spiros_Despina Kal
------------------------------------------------------------------------------------------------------------------
Group 7 proposes:
Kostas
Dimitra
David
Lucas
The faucets of Hero of Alexandria
Four taps fill a tank with water. When only one tap is running, then the first one needs a day to fill the tank, the second one needs two days, the third one three days and fourth one four days. If all the taps run simultaneously, how much time will be needed to fill the whole tank?
Group 6 answers: Michi_Martin_Hlias_Aggelos K
---------------------------------------------------------------------------------------------------------------
Group 8 proposes:
- Max
- Zoe
- Celia
- Andros
On the isosceles triangle ABC, with AB=AC, with the point P in AC so BP is perpendicular to AC, and that Q the point of BC so PQ is perpendicular to BC
if BP= 5 and PQ= 3 , find the lenght of the sides of the triangle ABC.
Group 2 answers: Yaiza_Lorena_Marina_Irene
--------------------------------------------------------------------------------------------------------------
Group 9 proposes:
Mara ,Sandra, Xenophon, Anastasis
Find The Area Of The Red Triangle!
Group 5 answers: Sheila_Ismael_Issidore_Angel O
---------------------------------------------------------------------------------------------------------------
Group 10 proposes:
- Despina
- Aggelos
- George
- Eva
- Raquel
- Marina
We have four boxes of chocolates, each of the four boxes contains the same quantity. The four boxes together have less than 90 chocolates, but three of them have more than 65
chocolates.How many chocolates does each box contain?
Group 7 answers: Luka_David_Dimitra_Konstantinos