Mark and Amanda's restaurant bill comes to $64.50. They are planning to ti[ the waiter 20%. How much money should they leave the waiter for a tip?

They should leave $12.90 or round up to $13

Step-by-step explanation:

To find out the tip amount:

Convert 20% to .20

Multiply .20 x 64.50

=12.9

i think it is c hope that

there is only one way to arrange all the eight relative to each other because they are not distinct. we have

now there are nine places to place an (and not more than one in one place).   because we have four symbols, we need to choose four of these nine places to insert an . order does not matter because the are not distinct.

thus there are 1 · c(9,4) ways, or, if we calculate it,

thus there are 126 ways to form such "words."