Question

uma urna contém bolas numeradas de 1 a 50. Calcule:
a) a probabilidade de ser sorteada uma bola cujo numero seja par ou multiplos de 5
b) a probabilidade de ser sorteada uma bola cujo numero seja par e maior que 10 ou menor numero primo

Answer 1

a) Há de 1 a 50  vinte e cinco números pares e cinco múltiplos de cinco não pares.

casos favoráveis = 25 + 5 = 30
casos possíveis = 50

P = 30/50     P = 3/5 ou 3 em 5

b) Há vinte números pares maiores que 10 e o menor número primo é 2

casos favoráveis = 20 + 1 = 21

casos possíveis = 50

P = 21/50

Answer 2

a)                                                                                                                                      P(A)=( 2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,50)=25                                                                                                                                  P(A)= 25/50=1/2                                                                                                                             P(B)= ( 5,10,15,20,25,30,35,40,45,50)= 10                                                                     P(B) = 10/50= 1/5                                                                                                            P(A) inter p(B)=( 10,20,30,40,50=5                                                                                                                       (A ) p(A)inter p(B)= 5/50= 1/10                                                                                                                                  p(A ) + p(B) - p(A) inter p(B)=                                                                                 1/2 +     1/5  -  1/10= 3/5                                                                                                ou 60%                                                                                                                          b) p(A) par maior que 10= ( 12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,50)=20                     p(A) =20/50=2/5                                                                                                               p(B) menor numero primo=( 2) =1 p(B) = 1/50                                                               p( A) + p (B) =                                                                                                          2/5   +  1/50= 21/50 ou 42%