Add all the marbles up: 6 + 14 + 7 = 27 marbles
There are 6 yellow marbles and 14 red marbles. 6 + 14 = 20
The probability of selecting a red/yellow marble is a 20 out of 27 chance.
1. When there are two events that need to happen, we must multiply the probability of each event happening.
Shawn losing to Mike: 5/8 chance
Shawn losing to Tim: 2/7 chance
5/8 × 2/7 = 10/56 = 5/28
There's a 5/28 chance of Shawn losing to Mike and Tim.
I don't know #2, sorry :/
Hope this helps!
12. Both sides of the equation are equal and if 18 is half of 36 then 6×2 will give you the value of X