## HotPinkGirl one year ago A sandwich shop offers the toppings shown below. how many 2 topping sandwiches can you make? ham turkey lettuce tomato bacon cheese mustard A. 14 B. 21 C. 28 D. 36

1. HotPinkGirl

@amistre64 @campbell_st @Hero @Michele_Laino @satellite73

2. anonymous

i think there is 36

3. anonymous

im not sure thogh tell me if im right

4. campbell_st

so my question is does ham and ham count as a 2 topping sandwich

5. Hero

6. anonymous

no

7. anonymous

it has to be like ham and letuce or cheese and bacon stuff like that

8. campbell_st

wow... who's question is it...?

9. HotPinkGirl

mine

10. HotPinkGirl

11. campbell_st

I don't think so..?

12. HotPinkGirl

then can you help me figure out what the answer is

13. campbell_st

is order important.... as in which topping goes on 1st..?

14. HotPinkGirl

i dont think so

15. campbell_st

so is ham and mustard the same as mustard and ham...?

16. HotPinkGirl

i guess

17. campbell_st

so if order isn't important.... then you have a combination question, selecting 2 items from 7

18. campbell_st

19. HotPinkGirl

a little bit

20. campbell_st

the formula is $^nC_{r} = \frac{n!}{r!(n - r)!}$ n = the number of items you select from r = the number of items you have to select... your calculator probably has a combinations function. so you have n = 7 and r = 2 hope it helps

21. HotPinkGirl

is it 14?

22. campbell_st

that seems the most obvious solution to me

23. campbell_st

just do the calculation....

24. HotPinkGirl

thanks

25. campbell_st

oops... I ment on how to do the question... and I'd say 14 is also incorrect

26. HotPinkGirl

oh

27. HotPinkGirl

i still dont get it, would it be 21???@campbell_st

28. HotPinkGirl

@Hero

29. campbell_st

well That's my best guess at an answer

30. HotPinkGirl

ok, thanks