Mary rolls 2 number cubes with sides numbered from 1 to 6.
if she rolls a 3 on one of the cubes , what is the probability that the sum of the numbers facing up on both cubes is greater than or equal to 5? express your answer as a decimal rounded to the nearest hundreth.
We know what one cube is, so the other cube is what matters
the second cube has 6 possible outcomes
1 2 3 4 5 6
If that result on the second cube is
2 3 4 5 or 6 , we win
so 5 good results out of 6 equally likely outcomes.
5/6 = .83
.83
To find the probability, we need to calculate the number of favorable outcomes and the number of possible outcomes.
If one of the cubes has already rolled a 3, there are four possibilities for the other cube to roll (1, 2, 4, or 5) in order to get a sum greater than or equal to 5.
The total number of possible outcomes is 6 for each cube, so there are 6 x 6 = 36 total possible outcomes.
Therefore, the probability is 4/36 = 1/9, which is approximately equal to 0.11 when rounded to the nearest hundredth.
To find the probability that the sum of the numbers facing up on both cubes is greater than or equal to 5, given that she rolled a 3 on one of the cubes, we need to determine the total number of favorable outcomes and the total number of possible outcomes.
Let's first count the total number of possible outcomes when rolling the two number cubes. Since each cube has 6 sides numbered from 1 to 6, there are 6 possible outcomes for each cube. Thus, the total number of possible outcomes is 6 x 6 = 36.
Next, let's find the total number of favorable outcomes. If Mary rolls a 3 on one of the cubes, we need to determine the number of possible outcomes on the second cube that would result in a sum greater than or equal to 5. Since the other cube has numbers from 1 to 6, the possible outcomes on the second cube that satisfy the condition are 3, 4, 5, and 6. Therefore, the total number of favorable outcomes is 4.
To calculate the probability, divide the total number of favorable outcomes by the total number of possible outcomes:
Probability = Number of favorable outcomes / Number of possible outcomes
Probability = 4 / 36
Simplifying this fraction gives the probability:
Probability = 1 / 9
Rounded to the nearest hundredth, the probability is approximately 0.11.