Intro urna sunt 24 de bile albe si 16 bile negre. se extrage la intamplare o bila . probabilitatea ca bila extrasa sa fie alba este..

Step-by-step explanation:

Given parameters:

Number of white balls  = 24

Number of black balls  = 16

Unknown:

The probability that white ball is drawn at random = ?

Solution:

The probability of an event is the likelihood of such an event to occur. That an event will occur has a probability of 1, it will not occur have a probability of zero.

In this problem, the total number of outcomes of drawing any ball has sample space of (24 + 16)outcomes  = 40outcomes.

Probability of an event  =

                  Pr(white balls) =   =

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons