Answer:
Step-by-step explanation:
29 5x+8+x+4=90
6x=78
x=13
30 3x-7+11x-1=90
14x=98
x=7
31 3x+x+8=180
4x=172
x=43
32 6x-1+5x-17=180
11x=198
x=18
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: 
Answer: yes it is
Step-by-step explanation:
This what got , hope it helps