Question

Cards each marked with one of the numbers 4, 5, 6, ..., 20 are placed in a box and mixed thoroughly. One card is drawn at random from the box. What is the probability of getting an even number?

Answer 1

Cards are marked with one of the numbers 4, 5, 6…20 are placed in a box and mixed thoroughly. One card is picked at random.

TO FIND: Probability of getting an even number on the picked card.

Total number of cards is 20-3=17

Cards marked even number are 4,6,8,10,12,14,16,18,20

Total number of cards marked even is 9 

`"We know that PROBABILITY" = "Number of favourable event"/"Total number of event"` 

Hence probability of getting an even number on the card `=9/17`