15 = 2w - 5
15 + 5 = 2w
20 = 2w
20/2 = 2w/2
10 = w
w = 10
1/3
mark tom travis
tom travis mark
travis mark tom
how many boys 3
how many total 9
3/9 = 1/3
Answer:
To multiply mixed numbers, first change any mixed number to an improper fraction. Then multiply the numerators together and the denominators together, as shown in Example .
Step-by-step explanation:
Consider such events:
A - slip with number 3 is chosen;
B - the sum of numbers is 4.
You have to count 
Use formula for conditional probability:
1. The event 
consists in selecting two slips, first is 3 and second should be 1, because the sum is 4. The number of favorable outcomes is exactly 1 and the number of all possible outcomes is 5·4=20 (you have 5 ways to select 1st slip and 4 ways to select 2nd slip). Then the probability of event is
2. The event 
consists in selecting two slips with the sum 4. The number of favorable outcomes is exactly 2 (1st slip 3 and 2nd slip 1 or 1st slip 1 and 2nd slip 3) and the number of all possible outcomes is 5·4=20 (you have 5 ways to select 1st slip and 4 ways to select 2nd slip). Then the probability of event is
3. Then
Answer: 
