Idk sorry I would answer if I did but I need points to ask a question
He's using the graduated cylinder method. I think the volume might be between 15 and 20. (It's kind of not obvious...)
Answer:
420/30=14 beats per second, meanin 1680 beats is your answer.
Step-by-step explanation:
<span>D. r + (-r) = 0
</span>
The additive inverse<span> of a number a is the number that, when added to a, yields zero. This number is also known as the opposite.</span>
