Cards are numbered 1 to 100. Find probability of getting an even number or

an odd number

Since cards are numbered from 1 to 100 total number of cards is 100

in 100 numbers half of them will be even and half odd 

So, number of cards numbered even = 100/2 =50

probability of getting an even number = 50/100 =1/2

Similarly , probabilty of getting an odd number = 50/100 =1/2