I do not agree. If you divide 240 by 30, it would be 8 heartbeats, which is absurd. It's impossible for something to survive with 8 heartbeats per 30 seconds. In order to get the CORRECT answer, divide 240 by 60 seconds. This would give you 4 heartbeats per second. Then, multiply it by 30 seconds, which would give you 120 heartbeats.