Urgent please help! Charlotte and Muhammad sit on the 10-member board of directors...

[Firas]

Charlotte and Muhammad sit on the 10-member board of directors for company P. If the board is to be split up into two 5-person subcommittees, what percent of all the possible subcommittees that include Muhammad also include Charlotte?

ans : 28.571%

 

[Dr.Peterson]

Charlotte and Muhammad sit on the 10-member board of directors for company P. If the board is to be split up into two 5-person subcommittees, what percent of all the possible subcommittees that include Muhammad also include Charlotte?

ans : 28.571%

Please show us your own thinking, even if you are sure it is wrong or have not reached an answer. We need to see where you are in order to get you from there to the goal. What methods are you considering?

I would probably do this by counting the total number of ways to form a subcommittee that includes M, and the number that include both M and C. Have you tried that?

 

[Firas]

If Muhammad is already there, 9C4 to choose others : 9! / 4! x 5! = 126

After Charlotte is chosen, we have 8C3 ways for other 3 : 56 ways

100 % - 126
1 % - 1.26
1.26 - 1%
56 - 44.444

where did i go wrong

 

[Dr.Peterson]

If Muhammad is already there, 9C4 to choose others : 9! / 4! x 5! = 126

After Charlotte is chosen, we have 8C3 ways for other 3 : 56 ways

100 % - 126
1 % - 1.26
1.26 - 1%
56 - 44.444

where did i go wrong

You have the right combinations.

But why are you subtracting? And how can you subtract a number (126) from a percentage (100)?? I can't make any sense of what you did there.

You were asked to find what percentage one number is of the other. You've got those two numbers; just divide!

 

[Firas]

You have the right combinations.

But why are you subtracting? And how can you subtract a number (126) from a percentage (100)?? I can't make any sense of what you did there.

You were asked to find what percentage one number is of the other. You've got those two numbers; just divide!

yeah even i cannot understand. so can you please show how you did it (with mathematical statements)?

 

[Steven G]

yeah even i cannot understand. so can you please show how you did it (with mathematical statements)?

No, sorry, but we will not show how to do the problem. You have to do the problem and if you get stuck we will try to get you back on track. Try to first find this--How many ways can you form a 5 member committee from 10 if you want to special people (from the 10) to be on the committee. Please respond with your work and we can help from there.

 

[Dr.Peterson]

yeah even i cannot understand. so can you please show how you did it (with mathematical statements)?

Please answer my questions if you want help; otherwise, we can't tell where your thinking is wrong. Our goal is to help you learn to think, not just to give free answers from which you won't learn.

So, tell us why you did what you did, or else try again, thinking more clearly this time and explaining it. (Sometimes having to explain your thinking can help you think better!)

 

[Firas]

Reply

Please answer my questions if you want help; otherwise, we can't tell where your thinking is wrong. Our goal is to help you learn to think, not just to give free answers from which you won't learn.

So, tell us why you did what you did, or else try again, thinking more clearly this time and explaining it. (Sometimes having to explain your thinking can help you think better!)

100 % = 126
1 % = 1.26
1.26 = 1%
56 = 44.444

i meant like units and not subtraction. still, the answer is different

 

[Deleted member 4993]

Charlotte and Muhammad sit on the 10-member board of directors for company P. If the board is to be split up into two 5-person subcommittees, what percent of all the possible subcommittees that include Muhammad also include Charlotte?

ans : 28.571%

If you choose 5 member committee from those 10 people: following situations can arise

1) None of those two are included in this committee (then the committee with left-over has both of them)

2) One of those (only) included in this committee

 

[Dr.Peterson]

100 % = 126
1 % = 1.26
1.26 = 1%
56 = 44.444

i meant like units and not subtraction. still, the answer is different

Please say in words what you are thinking. Just writing numbers doesn't let me see what you have in mind. And don't use either "-" or "=" when you don't really mean that two things are equal. It simply is not true that 56 is equal to 44.444!

But whatever you are doing, you do seem to get the correct answer, 44.444%. Others are trying to get you to see what I think you already see, namely that 9C4 and 8C3 are involved. The question is, how do you use those to answer the question, "what percent of all the possible subcommittees that include Muhammad also include Charlotte?" As you have said, there are 126 ways to include Muhammad, 56 of which also include Charlotte. So, what percent of 126 is 56? The answer is 56/126 * 100% = 44.44%. (As a fraction, this is 4/9.)

I don't think their answer (28.571% = 2/7) is correct; but from the start I was unsure of the meaning of the question, so perhaps I am interpreting it wrong (especially if you translated it from another language, and missed a detail). They split into two subcommittees (presumably mutually exclusive), but then they ask about the number of possible individual subcommittees, not ways of dividing. (Each way of dividing produces two subcommittees.) That, however, doesn't lead me to a different interpretation in which 2/7 is correct.

Maybe somebody else sees a "correct" interpretation.

 

[Firas]

i got the same answer. but i did a longer way to get it.

expressing 126 as 100%, i used that to find 1% and then how much 56 is of that.

If you didnt see, i got the answer of 44.444 also.