Question

Intr-o urna de votare sunt cel mult 200 buletine. Daca sunt numarate cate 6, cate7 sau cate 8, atunci de fiecare data ramin cate 5 buletine. Afla cate buletine sunt in urna

Answer 1

fie x= nr de buletine
x≤ 200
x= 6a+ 5
x= 7b+5
x= 8c+ 5
x-5= 6a=7b=8c
⇒x-5 =[6,7,8]k, unde k∈N
deci x-5= 168k
x= 168k+ 5
dar x e cel mult 200⇒k=1

si x= 168+ 5= 173

O seara buna!