Scenario 1 is dependent. Each time you draw from the jar, the selection changes because you’re not replacing the previous marble. Scenario 2 is independent because the marbles are put back in the jar, so the odds do not chance.
In scenario 1, you have a 13/26 (50%) chance of selecting a blue marble. Now that you’ve removed that blue marble, there are now 13 red and 12 blue, so your chance of getting blue is 12/25 (48%). So your chance of getting two blue in a row is 13/26 x 12/25= .5 x .48= .24= 24%. Whereas in scenario 2, you have a 13/26 chance of getting a blue marble each time. So your chance of getting two blue in a row is 13/26 x 13/26= .5 x .5= .25= 25%. So you have a higher chance (by 1%) of getting two blue in a row in scenario 2 than 1
So first you find out how much money he makes per week, by doing 7.5 x 20 you will find that. Now you need to find how many weeks it will take, find this by dividing 1200 by the amount he makes per week and you will end up with 8.
