Answer: Benjamin's heart beats 85 times in 60 seconds.
Step-by-step explanation: For this problem we will be writing a ratio.
The ratio 17:12 represents this situation because the ratio states that Benjamin's heartbeat beats 17 times in 12 seconds. We want to know how many times his heart beats in 60 seconds.
Simply keep adding 17 to the left side of the ratio and 12 to the right side.
17:12
34:24
51:36
68:48
85:60
So, in 60 seconds Benjamin's heart will beat 85 times.