THE FIRST ONE AND THE LAST ONE
The numbers DO differ by 10 if they are
- 1 and 11
- 2 and 12
- 3 and 13
- 4 and 14
- 5 and 15
Each outcome technically has two ways of occurring, but since we're taking two marbles at a time, that would be the same as saying, for instance, that drawing 1 and 11 is the same as drawing 11 and 1. We only count such an event once.
So the answer is (a) 5.
Answer:

Step-by-step explanation:
There are

different ways to select the four numbers between 1 and 42. Only one of this ways is correct (successful to win).
There are 30 different ways select the single number between 1 and 30. Only one of them is correct.
The probability of winning the jackpot is

Answer: 504
Step-by-step explanation:
When we select r things from n things in a order , we use permutations.
Formula for permutation: 
Given : The number of family members who are potential kidney donors. = 9
Number of people needed to be selected for best match, a second-best match, and a third-best match ( in an order)=3
Then, the number of possible orders are = 

Hence, the number of possible orders 504.