Bill checks his pulse for 2 minutes and counts 198 beats. What is his heart rate in beats per hour?

5940 beats per hour

Step-by-step explanation:

1 hr = 60 mins

we are given that 2 mins : 198 beats

the unknown beats per hour = x

2 mins : 198 beats

60 mins : x beats

to get from 2 to 60 multiply by 30, so do the same to the other side

198 × 30 = 5940 beats

there are 5940 beats per hour

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."