There are eight prime numbers between 1 and 20.
2, 3, 5, 7, 11, 13, 17, 19
If you randomly choose in number then you have an 8 in 20 chance of selecting a prime.
The probability is selecting a Prime number is 8/20 or 0.4
Chat with our AI personalities
The probability is 8/20.
There are 8 out of 20 numbers that are prime, so 8/20, or 2/5.
The probability of selecting a red card is 26 in 52 or 1 in 2. The probability of selecting an even card is 20 in 52 or 5 in 13. The probability, therefore, of selecting a red even card is 1 in 2 times 5 in 13 or 5 in 26.
The theoretical probability of randomly picking each color marble is the number of color marbles you have for each color, divided by the total number of marbles. For example, the probability of selecting a red marble is 3/20.
1 out of 20 this is because there are 20 numbers in total, and there is only one 7 in there. (Assuming that there is the same probability for each number to be chosen, and that 17 is excluded as an affirmative outcome)