## anonymous one year ago *** help*** a new exhibit is scheduled to open at the local museum. museum officials expect that 5000 people will visit the exhibit in its first week, and that the number of visitors will drop by 10 people per week after the first week during the first 6 months. find the total number of visitors expected in the exhibits first 7 weeks

1. mathstudent55

In the first week there will be 5000 visitors. In the second week, there will be 10% fewer visitors than in the first week. Can you calculate how many visitors there will be in the second week?

2. anonymous

5000/.10=50000

3. anonymous

right?

4. anonymous

@mathstudent55

5. mathstudent55

No. In math, in addition to solving a problem using some method, you need to look at your answer and see if it makes sense. If there will be 10% FEWER visitors in the second week, how can you end up with 10 times more visitors?

6. mathstudent55

This is how you do it.

7. mathstudent55

In the first week, there are 5000 visitors. Call the initial number, 5000, 100%. In the second week, there will be 10% fewer visitors. That means in the second week, there will be 100% - 10% = 90% of the 5000 visitors.

8. mathstudent55

Now we calculate 90% of 5000. 90% of 5000 = 90/100 * 5000 = 0.90 * 5000 = 4500

9. anonymous

ok

10. mathstudent55

Ok so far?

11. anonymous

correct

12. anonymous

but the number that you're getting is decreasing. the answer choices are, 34,730, 24,850, 34790, 29,850

13. mathstudent55

|dw:1439166621075:dw|

14. anonymous

so it goes down by 500

15. mathstudent55

You see the table above. That is where we are so far in solving this problem. We know how many visitors there will be in the first and second weeks. Now we need to find the numbers for weeks 3 through 7. Then we add all numbers up.

16. anonymous

ok got you!

17. mathstudent55

You asked a good question. The answer is no. The number goes down by 10% of the previous week. Since the first week has 5000 visitors, 10% of 5000 is 500, so from week 1 to week 2 it went down by 500.

18. mathstudent55

Now to find the number for week 3, think of week 2 as 100%. What is 90% of 4500?

19. anonymous

4050

20. anonymous

.90*4500

21. mathstudent55

You are always losing 10% of the previous week, but each week, the number is decreasing, so 10% of the previous week is going to be less and less each week that goes by.

22. mathstudent55

Exactly. You put it on our table. |dw:1439167056423:dw|

23. mathstudent55

Now start with 4050, and find 90% of that number. 0.90 * 4050 = 3645 |dw:1439167103110:dw|

24. mathstudent55

You see how you get the following week's number? Multiply each week's number by 0.9 Fill in the table's right column. Then add all numbers in the right column.

25. anonymous

ok doing it now.

26. anonymous

i ended up getting 22440.155

27. anonymous

|dw:1439167568272:dw|

28. mathstudent55

|dw:1439167579583:dw|

29. mathstudent55

I get 26,085. The problem is the answer is not in your choices.

30. anonymous

31. mathstudent55

Are you sure you copied the problem correctly?

32. mathstudent55

Ok

33. anonymous

and yes, thats what im trying to see.

34. anonymous

yes, it's copied word from word.

35. mathstudent55

Are you sure the number goes down 10% each week. There is a percent in the problem?

36. mathstudent55

37. anonymous

10 people per week

38. mathstudent55

I just reread it. The problem states the number goes down 10 people per week. I read it as 10 percent per week. My mistake. Sorry about that.

39. anonymous

lol it's fine. thank you for being patient with me. math gives me a headache

40. mathstudent55

That means it's a simpler problem. Let's use the same table, and clear out the second column except for the 5000 in the first week.

41. anonymous

ok cool

42. mathstudent55

|dw:1439168119386:dw|

43. mathstudent55

Now for each subsequent week, we just subtract 10 from the previous week. As you can see, this is an easier problem than I thought because of my misreading.

44. anonymous

|dw:1439168175356:dw|

45. anonymous

are you serious? lol i feel so dumb

46. anonymous

that was easy but reading it, i thought that i had to do more

47. mathstudent55

|dw:1439168205828:dw|

48. mathstudent55

Good job! Exactly. That's what I got. As you can see, it's not a difficult problem. Sorry to have complicated it above.

49. anonymous

lol no it's perfectly fine. i appreciate your help and patience

50. mathstudent55

You're very welcome.

51. anonymous

thank you! i have more problems, but i wont burden you. ill try to work them out first, but thank you!

52. mathstudent55

1. You are welcome. 2. Try your problems by yourself first. If you need help, don't hesitate to ask for it. 3. Helping is not a burden.