Twenty cards are numbered from 1 to 20. The cards are shuffled and then placed face down on the table. A card is drawn random. What is the probability that the number on this card is:
a) 14
b) an even number
c)less than 11
d)divisible by 5
e)a prime number
f)22 ?
If you are studying probability, you MUST be able to do these very simple questions.
State your answers and I will check them
ten eerste ---Proberen te beantwoorden
Twenty cards are numbered from 1-20. The cards are shuffled. A card is drawn. Find the probability that the card has:
A) an odd number
B) a multiple of 4
C) a prime number
D) a number greater than 30
E) a number divisible by 1
Express each probability as many ways you can
To solve this problem, we need to find the total number of favorable outcomes and divide it by the total number of possible outcomes.
Given:
Total number of cards = 20
a) Probability of drawing the card with number 14:
There is only one card with the number 14. So, the number of favorable outcomes is 1. The total number of possible outcomes is still 20. Therefore, the probability is 1/20.
b) Probability of drawing an even number:
There are 10 even numbers (2, 4, 6, 8, 10, 12, 14, 16, 18, and 20) out of 20 total cards. So, the number of favorable outcomes is 10. The total number of possible outcomes is still 20. Therefore, the probability is 10/20, which simplifies to 1/2.
c) Probability of drawing a number less than 11:
There are 10 numbers less than 11 (1, 2, 3, 4, 5, 6, 7, 8, 9, and 10) out of 20 total cards. So, the number of favorable outcomes is 10. The total number of possible outcomes is still 20. Therefore, the probability is 10/20, which simplifies to 1/2.
d) Probability of drawing a number divisible by 5:
There are 4 numbers divisible by 5 (5, 10, 15, and 20) out of the 20 total cards. So, the number of favorable outcomes is 4. The total number of possible outcomes is still 20. Therefore, the probability is 4/20, which simplifies to 1/5.
e) Probability of drawing a prime number:
There are 8 prime numbers (2, 3, 5, 7, 11, 13, 17, and 19) out of the 20 total cards. So, the number of favorable outcomes is 8. The total number of possible outcomes is still 20. Therefore, the probability is 8/20, which simplifies to 2/5.
f) Probability of drawing the card with number 22:
There is no card with number 22, so the number of favorable outcomes is 0. The total number of possible outcomes is still 20. Therefore, the probability is 0/20, which simplifies to 0.
Note: The probabilities can also be expressed in decimal or percentage form if desired.