how do you solve this? A dice is rolled twice. What is the probability of getting a multiple of 3 on the first roll or a total of 7?

530+30= 560 (all you do is at the total number of boys with the number of bikes girls have)

can you solve this ? Of 1000 students surveyed, 530 were boys and 180 had bicycles. Of those who had bicycles, 30 were girls. What is the probability that a student surveyed was a boy or had a bicycle?

To solve this problem, we need to find the probability of two events: getting a multiple of 3 on the first roll and getting a total of 7 on both rolls.

First, let's find the probability of getting a multiple of 3 on the first roll. A standard six-sided dice has two multiples of 3, which are 3 and 6. Therefore, the probability of getting a multiple of 3 on the first roll is 2/6 or 1/3.

Next, let's find the probability of getting a total of 7 on both rolls. There are six different combinations of two dice rolls that result in a total of 7: (1, 6), (2, 5), (3, 4), (4, 3), (5, 2), and (6, 1). Since there are a total of 36 equally likely outcomes when rolling two dice (6 outcomes for the first roll multiplied by 6 outcomes for the second roll), the probability of getting a total of 7 is 6/36 or 1/6.

To find the probability of either event occurring, we can add the probabilities together. So the probability of getting a multiple of 3 on the first roll or a total of 7 is 1/3 + 1/6 = 1/2 or 0.5.

Therefore, the probability of getting a multiple of 3 on the first roll or a total of 7 when rolling a dice twice is 1/2 or 0.5.