In a medical examination of students of a class,the following blood groups are recorded:

Blood group	$A, AB, B, O$
Number of students	$10, 13, 12, 5$

$A$ student is selected at random from the class. The probability that he/she has blood group $B$,is:

The probability of an event of a mango growing on an acacia tree is ..........

State whether each of the following statements is true or false:
$(1)$ For the probability $P(A)$ of any event $A$,$0 < P(A) < 1$.
$(2)$ The probability of the month of March having $5$ Sundays is $\frac{1}{7}$.
$(3)$ If the probability of an event $A$ occurring is $\frac{3}{7}$,then the probability of event $A$ not occurring is $\frac{4}{7}$.

The probability that a non-leap year should have $53$ Sundays is ............ (in $/7$)

$A$ recent survey found that the ages of workers in a factory is distributed as follows:

Age (in years)	$20-29$	$30-39$	$40-49$	$50-59$	$60$ and above
Number of workers	$38$	$27$	$86$	$46$	$3$

If a person is selected at random,find the probability that the person is under $40$ years.

$A$ recent survey found that the ages of workers in a factory is distributed as follows:

Age (in years)	$20-29$	$30-39$	$40-49$	$50-59$	$60$ and above
Number of workers	$38$	$27$	$86$	$46$	$3$

If a person is selected at random,find the probability that the person is $40$ years or more.