Question 45364
Suppose that you randomly select a two digit number (that is one of 00,01,01,...99) from a sequence of random numbers obtained by repeatedly spinning a spinner. 

What is the probability that the number selected is less than 10? 
00 to 09 is ten numbers.
00 to 99 is 100 numbers.
P(numbers less than 10)=10/100 = 0.1
-----------------------------------------

That the number selected is even or is less than 50. 
Prob(even or <50)=Prob(even)+Prob(<50)-Prob(even and<50)
=50/100 + 50/100 - 25/100 = 75/100
------------------------------------------
The number selected is even given that it is less than 50?
Prob(even given <50) = [prob(even and <50)]/[Prob(<50)]
[25/100]/[50/100)= 1/2

Cheers,
Stan H.