A bank teller has some stacks of bills. The total value of the bills in each stack

is $1000. Every stack contains at least one $20 bill, at least one $50 bill, and no

other types of bills. If no two stacks have the same number of $20 bills, what is the

maximum possible number of stacks that the teller could have?

(A) 9 (B) 10 (C) 11 (D) 4 (E) 8

So since only 20 dollar bills and the other one is a 50

then

so we find some combos that will work

five 20's make 100

we notice that we can only have 20's in multipules of 5 to make 100's becauause 4 20's makes 80 and 3 20's make 60 and 2 20's make40 and none of those add to 50 evenly to make 100's

(probably confusing but I hope you understand if you think about it)

so we have

5 20's = 100

10 20's=200

15 20's=300

20

25

30

35

40

45 20's=900

50 20's=1000

so how many multiplules did we have?

10

but wait, if we havve 1000 in all 20's we still need at least one 50 so we subtract 100

900:9

answe ris 9 stacks

answer is 9 stacks or A