Question

Juanita is playing a math game. The game includes 20 number tiles. One number is written on each tile, and a tile for each number from 1-20 is included. Juanita draws 1 tile, records the number, and does not replace the tile. She then draws a second tile and records the number. What is the probability that Juanita draws 2 prime numbers? (Write as a fraction)

Answer 1

Answer: 7/50

Explanation:

There are 8 prime numbers between 1 and 20

the probability of picking the first time is 8/20 = 2/5

if we pick a prime first, then there will be 7 without replacement which is a chance of 7/20

we then multiply both of them 2/5*7/20 to get 14/100 = 7/50