M-am gandit sa public o problema de matematica si perspicacitate in acelasi timp. Daca pentru rezolvarea problemei va trebuie mai mult de 5 minute inseamna ca mai aveti de lucru pe la matematica 🙂

Un elev participa la un concurs de matematica. Are de rezolvat 15 probleme. Pentru fiecare problema primeste 8 puncte. Pentru fiecare problema nerezolvata se scad **10** puncte. Dupa corectarea lucrarii obtine 70 puncte. Cate probleme a rezolvat corect ?

**ERATA: Pentru fiecare problema nerezolvata se scad ****2 puncte.
**

to John Smith: You are right, it was a mistake in the text. Excuse me !

pentru Madalina: Problema a fost publicata cu o eroare. Scuza-ma te rog !

to Janet Jackson: It was a mistake in the text. It hasn’t a right answer as was published. Excuse me !

He solved ten problems out of fifteen!

I’m I right?

And let me explain why!

Each solved problem is worth 8 points so total for all of them is 120 points ( 15*8=120 ).

The final score was 70 points.

120-70=50

50/10(the penalty for a unsolved problem)=5 unsolved problems!!!

Did I get it right???

Dear John SMITH, You are right.

I will hide your comment until some other friends of Monica will answer.

Actually I’m wrong and I did it on purpose as a set up! Hi, hi, hi!!!

The correct answer is: It’s a trick question! According with the algorithm it’s impossible to gain 70 points. It’s either 84 points for 13 correct answers or 66 points for 12 correct answers.

Anybody can explain why???

(15*8)-x=70

X=120-70

X=50 insemnand 5 probleme nerezolvate

rspunsul este 10 probleme rezolvate

Sorry Madalina, but your answer is wrong!

And I will explain why!

You said that he solved only ten problems, right?

If that’s the case he only earned 80 points!

10 problems solved x 8 points = 80 points

But let’s not forget that he also loses 10 points

for for each unsolved problem.

5 problems unsolved x 10 points = 50 points

So,if you do the math all the way to the end…

the fact is he only earned a total of 30 points not 70!!!

its a nonsens…its a math paradox

Monii!!, e scrisa corect problema?Nu e vre-o greasela pe undeva???Te intreb pentru ca eu cred akum,ca nu exista raspuns corect la aceasta problema.

Scuze Monii!Nu am fost atenta si am crezut ca tu ai postat problema. 🙂

Thank You John Smith!!!

But in a way i was right 😉

He solved ten problems:D

Ha! I knew it! Now it make sense!

Can you post more problems like this (but correct ones!)?

This is fun!!!

daca probl ar fi corecte

15X8=120

diferenta intre punctele maxim si cal real

120-70=50

punctuaj luat

8+10= 18

probl gresite

50:18=